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NATIONAL ADVISORY COMMITTEE
THE PREPARATION AND PHYSICAL PROPERTIES OF SEVERAL
ALIPHATIC HYDROCARBONS AND INTERMEDIATES
By Frank L. Howard, Thomas W. Mears, A. Fookson,
Philip Pomerantz, and Donald B. Brooks
National Bureau of Standards
TECH LIBRARY KAFB.NM
NACA TN No. 12kj
TABLE OF CONSENTS
APPARATUS . . ' '■ 2
Reaction Vessels . .............. 2
Hydrogenation Equipment 2
Sti lls 3
DETERMINATION OF PHYSICAL PROPERTIES k
PREPARATION OF MATERIALS 5
Preparation of G-rignard Reagents 5
2-MethyTbutane (Isopentane) •*•. • .• 7
2, 2-Dimethylpropane (Neopentane) ...... ... 7
3-Methylpentane ......... . 9
2, 2-Dimethyrbutane (Neohexane) 9
2-Methylpentane ................ 10
Investigation of Butene Alkylate ..... 10
2, 3-Dimethylpentane from Isooctane ..... 11
2,2,3-Trimethyrbutane (Triptane) 11
2,3,3-Trimethylpentane - 13
2,2,3-Trimethylpentane and 2,3,4-TrImethylpentane ....... it
2,3,5-Trimethylhexane . . , i . c 14
2,2,lt--Trimethylhexane . 17
# 2,l4--Dimethyl-3-Ethylpentane 19
2,2,3,3-Tetramethylpentane (Tetrane) . 20
2, 2, 3, 4-Tetramethylpentane and 2,3,3,4-Tetramethylpentane ... 22
Dimethyl -Zinc Synthesis of Three Tetramethylpentanes 2k
2,2,3,11- and 2,3,3,li-Tetramethylpentanes 25
# 2,l|--Dimethyl-3-Isopropylpentane (Trlisopropylmethane) 27
Pent ame thy lpentanes 29
2,2,5,5-Tetramethylhexane and 2,2,4,5-Tetramethylhezane .... 38
2,3-Dimethyl-l-Butene and 2, 3-Dimethyl-2-Butene k2
3-Methyl-2-Pentenes (cis and trans) kk
Investigation of Diisohutylene kk
Investigation of Hot-Acid Polymer (Shell Oil Company) k6
TABLES .' . . , . 52
NATIONAL ADVISORY COMMITTEE FOR AERONAT3TICS
TECHNICAL NOTE- NO. 12^7
THE PREPARATION AND PHYSICAL PROPERTIES OP SEVERAL
ALIPHATIC HYDROCARBONS AND INTERMEDIATES
^By Frank L. Howard, Thomas W. Mears, A. Fookson,
Philip Pomerantz, and Donald B. Brooks
, In the course of an- investigation of the knock ratings of aliphatic
hydrocarbons, pure paraffins and olefins were prepared in quantities
sufficient for engine tests. This report describes the methods of prep-
aration and purification of three pentanes, four hexanes, three heptanes,
four octanes, eight nonanes, seven decanes, four hexenes, five octenes,
six nonenes, six decenes, and a number of alcohols, ketones, esters, and
alkyl halides. Most of these compounds were highly purified. Physical
oonstants measured included freezing point, "boiling point and its varia-
tion with pressure, refractive index and density, and their variations
In 193^ the Automotive Section of the National. Bureau of. Standards
undertook an investigation of the. impurities present in the certified
lscoctane (2,2,^~trimethylpentane) used as a primary standard in the
knock rating of fuels. In the course of this .work, about a score of
paraffin hydrocarbons were isolated and thqir physical properties and
knock ratings were determined. (See reference 1.) The information ob-
tained in this work indicated that some of the higher paraffin hydro-
carbons should he decidedly superior to isooctane in knock rating.
The results of this work led to a research- project that was initi-
ated with the objective of preparing, in quantities sufficient for engine
tests, the paraffin hydrocarbons likely to he of interest as components
of combat aviation fuel. This project was begun in 1937 under Joint
sponsorship of the National Advisory Committee for Aeronautics, the Army
Air Forces, and the Navy Bureau- of Aeronautics and has been actively
prosecuted since that time. The results of portions of this investigation
2 NACA TN No . 12^7
completed prior to 19**0 hare been presented in references 2 to 5, and-
the syntheses and physical properties of a number of additional aliphatic
hydrocarbons are described in the present paper.
Since the objective of this work was the preparation of pure hydro-
carbons for engine testing to determine knock rating, it was generally
necessary to subordinate other considerations to this purpose. In many
cases, it was therefore not possible to make detailed studies of the re-
actions or to determine properties of some of the new or little-known
Acknowledgments are due the following people for aid and advice on
various phases of this work: Dr. Cecil E. Boord, Ohio State University,
Dr. George Calingaert and Dr. Harold A. Soroos, Ethyl Corporation Re-
search Laboratories, Dr. Nathan L. Drake, University of Maryland, Dr.
Merrill R. Fenske and Dr. Frank C. Vhitmore, Pennsylvania State College,
and Dr. Frederick D. Rossini, National Bureau of Standards.
Small-scale exploratory reactions were generally carried out in 5-
liter glass flasks. In some cases, where an unusually low yield of
final product was expected, 12-liter flasks were used. The use of these
larger flasks was discontinued in 19^, and reactions of this size were
then conducted in llj--liter brass double-walled vessels. For synthesis
on a larger scale, two copper reactors were used initially. Each of
these reactors had a capacity of 60 liters and was double walled. Water
at any desired temperature between 5° and 75° C could he circulated in
the space between the walls to control the temperature of the reaction.
The reactors were equipped with multiple -paddle stirrers (60 to 200 rpm),
reflux condensers (multiple copper tube), separatory funnels for addi-
tion of reactants, and draw-off valves for removal of products. These
reactors were used until early in 19^, when two 50-gallon kettles (one
glass lined, one stainless steel) were put into service. The copper
reactors were then used as distillation receivers in conjunction with
the large kettles. The large kettles were standard commercial items
and were installed so that any temperature "between 5° s*id 150° C could
"be maintained in the jackets.
Hydrogenation reactions were accomplished in high-pressure hydro-
genators, designed after those described by Adkins in reference 6.
MCA TN No. 12V7
Three sizes were used, with capacities of 1, 3, and 20 liters. The cat-
alyst used vas a coxmnercial nickel-on-kieselguhr preparation, which
proved to "be economical and efficient. No difficulty was encountered in
hydrogenating any of the materials, provided they were halogen- free .
Most, of the hydrogenation reactions took place at temperatures "below
l60° C and pressures "below 2000 pounds per square inch.
For convenience, the various stills used in this work are desig-
nated in the text "by numbers. The salient features of these stills are
given in ta"ble 1. Some of these columns are no longer in use, having
"been supplanted "by others of later designs. Operations formerly per-
formed in Columns 1 and 2 were later carried out in 19 and 20, and Col-
umns 8 and 9 were replaced "by 17 and 18. Column 10 was abandoned in
I9U2, when Column 11 was put into operation. Columns 3 to 7 were re-
placed "by 21 to 27 late in 19^5.
Still 1 .- This still is of the. total-reflux, intermittent take-off
type, and has "been previously described in reference 5. The reflux rate
was approximately 1500 ml per hour in most cases, the take-off rate "be-
ing governed "by the composition of the charge and the purity desired in
the product. Samples of 78 ml each were removed" automatically at prede-
termined intervals varying from 0.5 to 2k hours. The efficiency is ap-
proximately ninety to ninety-five theoretical plates, and the' hold-up is
260 ml. •
Still 2 .- The column of this' still consists of 150 actual plates,
following the design "by J. H. Brunn. (See reference 7.) The volume of
each fraction removed was 65 ml. Reflux rate was a"bout 800 ml per hour.
This still has also "been described in reference 5* Th© mechanisms of
operation and sample removal are the same as for Still 1. ' In" "both
Stills 1 and 2 the head temperature was followed' during the 'day "by means
of a platinum resistance thermometer, and the timing operations were
scheduled so that samples were .removed when this temperature (corrected
to 760 mm Hg) "became reasonably constant (generally to within a change
of less than .005° C per hr) .
Stills 3 to 9 .- Small stills patterned after those described "by
Whitmore and. Lux (reference 8) . were used to remove other from reaction
mixtures, for purification of intermediates, for preliminary purifica-
tion of final products, and for fractionation of small charges. These
stills are designated as, 3 to 9 in ta"ble 1.
Still 10 .- Prior to the construction of other large-capacity stills,
Still 10 was used for .preliminary fractionation of commercial synthetic
crudes. The pot was part Qf a domestic ho't-water tank, the column a
k NACA TN No. 12^7
length of 2-inch pipe. The take-off was governed "by a l/8-inch needle
Still 11 .- In order to have a higher-oapacity, higher-efficiency
still than 10, Still 11 was constructed. The entire still is made of
monel metal. The reflux rate Is about h liters per hour, as measured by
gain in temperaturo of the condenser water; The take-off rato is gov-
erned "by a commercial l/8-lnch solenoid valve, operated "by an automatic
timing device. The efficiency of the still is about sixty-five theoret-
ical plates under operating conditions ( 3 .5 to h .5 liters per hr reflux) .
Safety devices include overflow tanks for the salvaging of material dis-
tilled through the condenser if the water is accidentally cut off, a
product overflew tank for retaining material which may he delivered "be-
cause of faulty operation of the solenoid valve, and a-pot-tezuperature-
limit control. All openings to the still are vented to the outside of
' Stills 12 to l6.- These columns were oonstructod for analysis of
commercial crudes, purification of large quantities of material, and
isolation of hydrocarbons from commercial mixtures. These were put into
operation in 19*K3, and later (19^5) Column 11 was lengthened by k feet
and added to the group. The take-off on all these stills is governed by
a timer and small solenoid valves. Condensers In the larger columns are
of the multiple cold-finger type. The columns are heated by resistance
wire controlled by variable transformers. Temperatures are measured by
copper-constantan thermocouples. Safety devices include overflow tanks,
automatic pot-temperature-limlt control, forood ventilation, automatic
carbon-dioxide fire control (controlled by thermal-plugs), and automatic
warning if the atmosphere approaches a combustible mixture. The pots of
Stills 12 to 16 are made of mild steel'. The columns of 12 and 13 are
made of galvanized pipe, and the columns of Ik and 15 are made of stain-
less steel. Condensers are of copper, brass, or monel metal.
KETERMINATIOIf OF PHYSICAL PROPERTIES
From the plots of refractive indices, boiling points, or freezing
points of fractions with respect to volume of distillate, those fractions
containing the best material were selected and used for the determination
of physical constants.
The methods used for the determination of physical constants have
been described in referenoe k. The freezing-point apparatus was modified
In December 19kk, so that additional control of the rate of cooling could
be obtained. This was done by installing a pumping system on the evacu-
ated chamber surrounding the sample, so that the rate of cooling oould be
governed by the pressure in the evacuated chamber. This modification of
NACA TIT JTo . 12^7 5
the equipment has "been adequately described "by Mair (reference 9) .
Table 2 lists the measured physical properties of the compounds de-
The freezing-point data on 2,2,5,5-tetramethylhexane are considered
representative, and are illustrated, in figure 1. Boiling-point data on
four compounds are shown in figure 2. These figures are presented as
typical examples of measured physical properties. Eefractive indices
were measured on an Abbe type (Talentlne) refraetomster until 19^3 when
a Bausch and Lomb precision-oil r6fraotometer (also Abbe type) was put
into use. An estimate of the purity of the Individual compounds may be
made from the data listed in table 2 under the heading £T:20 to 80 per-
cent, vhich Indicates the number of degrees difference between the tem-
perature at which 20 percent of the material had distilled and the tem-
perature at which 30 percent had distilled. The presence of peroxides
In the olefin samples tended to make this difference extraordinarily
PKEPAP.ATI0N OF MATERIALS
The preparation of Grignard. reagents in large quantities (up to
339 moles) has been found to be subject to the' same limitations as the
preparation of small amounts, except that the yields, in general, are
slightly larger. The methods used in typical runs of representative
members of the aliphatic series aro given as follows, and are not re-
peated in the discussion of the various syntheses. Decomposition of
reaction complexes formed by the action of Grignard reagents on various
compounds followed the classical methods and need not be repeated.
Methylmagnesium bromide .- To the reactor was added 100 gram atoms'''
(2 A3 kg) of magnesium turnings and enough ether to cover the magnesium.
A small amount of methyl bromide was added . If reaction did not start
Immediately, a little methyl iodide (or previously prepared Grignard
reagent) was added. After reaction had been initiated the stirrer was
started, and methyl bromide from a cylinder supported from a steelyard
was allowed to flow through a coll of copper tubing surrounded by a dry-
ice bath where it condensed and dropped Into the reaction mixture . Flow
was regulated by a small needle valve. After the reaction was well
started, cooling water was admitted to the ■ jacket, and an excess of
methyl bromide was added as fast as it would rsact. During the addition
of methyl bromide, ether was added In 2 -liter portions until the total
ether added was 20 liters ( 200 ml per gram atom of magnesium) . The
amount of methyl bromide added was determined by the loss of weight of
the cylinder, and it was found that practically no methyl bromide was
lost during the operation. After addition of methyl bromide was
6 MCA TN No . 1247
complete, the reaction mixture was warmed for 2 to 3 hours. If the mix-
ture contained sludge or pieces of unreacted magnesium, it was allowed to
stand until the sludge had settled, and then the clear solution was si-
phoned off. The sludge was next washed with dry ether and allowed to
settle, then the siphoning procedure was repeated. If the amoung of
sludge was small, this last operation was carried out advantageously in
a separatory funnel, in which the sludge could he drawn off easily.
The yields varied from 88 to 95 percent, "based on magnesium, as de-
termined "by titration. Similar yields were realized when ethyl magnesium
chloride was prepared, hut in this case slower addition of halide was
necessary in order to avoid the formation of appreciable amounts of
Isopropylmagnesium chl oride.- Magnesium turnings (1.5 kg, 6*3 gram
atoms) and 5 liters of ether wore placed in the reactor, and reaction
was started "by the addition of a small amount of lsopropyl chloride •
After the reaction was initiated, the stirrer was started and 1 liter
of lsopropyl chloride in 2 liters of ether was added slowly. After this
first charge of chloride was complete, 5 liters of ether and the rest of
the magnesium (1.5 kg, 63 gram atoms) were added, and cooling water was
circulated through the jacket. Then the rest of the chloride and ether
was added in the ratio of 1 liter of chloride for 2.0 to 2.5 liters of
other, until a total of 125 moles of chloride and 37.5 liters of ether
had "been used. This addition was carried out as fast as possible, still
keeping the reflux from the condenser dropwise and not in a steady stream.
About 35 hours were required for a 125-mole run. After removal of the
clear solution from the sludge, the yield, calculated from titration data,
amounted to 90 to 93 percent of the theoretical quantity'.
t-Butylmagnesium chloride .- This preparation was carried out in es-
sentially the same manner as descrihed for the preparation of isopropyl-
magnesium chloride, except that the addition of chloride was necessarily
slower In order to retard formation of hexamethylethane, isohutylene, and
diisohutylene. A 70-mole run required approximately 35 hours. The lat-
ter half of the chloride added was more dilute than the first half (ref-
erence 10) and the rate of addition was slowed up progressively as the re-
action neared completion. The Jacket of the reactor was not cooled so
much in this preparation as with the less highly "branched halidee. The
tendency of t -"butyl chloride to form sludge is much greater than that of
the simpler halldes, although many runs were made in which practically no
sludge was observed. The yields varied from 80 to 92 percent.
One gallon of commercial n-pentane was fractionated in Still 1.
From this distillation there was obtained 1792 ml of material, the
NACA TN No . 12U7 7
fractions of which had e refractive index nj^° of 1-357^ to I.3575. A
"■best", sample was selected for determination of physical constants.
One gallon of commercial isopentane was fractionated In Still 1.
There was obtained 2200 ml of material, np 20 = 1.3535 to 1.3536, which
was collected while the head temperature of the column was 27. 87 to
27 .88° C . Later a total of kj liters of high-purity material was pre-
pared from the same source "by fractionation in Still 11.
In 1933, Whitmore and Fleming (reference 11) described the prepara-
tion of neopentane "by reaction "between methytoagnesium chloride and
t-butyl chloride in toluene at 14-5° to 50° C. Yields of k-2 to 50 percent
were reported. ' Iin the present work, a method is described whereby some-
what larger .yields of purer product were obtained.
In this work, neopentane was prepared "by action of dimethyl zinc on
t-butyl chloride in toluene at 5° C. The advantage of causing reaction
at this temperature, rather than the often used higher temperature (35°
to 50° C) .for reactions of this type has "been previously demonstrated.
(See reference 2.) Dimethyl ' zinc was -prepared in the mariner described
in reference 2; however, certain Improvements in the technique of han-
dling this material have been made.
A 5-liter, single-neck flask, which was used for dimethyl- zinc prep-
. aration, was placed In : an oil bath and fitted- with a U00 -millimeter
reflux condenser ; . To the top of the condenser was attached a bridge of
10-millimeter glass tubing which led. to the top of a similar reflux con-
denser attached to a 5-liter, threB-neck flask. This latter flask, Into
which dimethyl zinc was distilled, was situated in a cold-water bath and
was provided with a separatory funnel (500 ml) and a stirrer. A side
arm on the bridge provided for the ' introduction of Inert gas (carbon
dioxide) . ...
The zinc-copper couple from 960 grams of zinc dust and 120 grams of
cupric oxide was placed in' the one -neck flask, and 1100 grams (7.75
moles) of methyl iodide added. The temperature of the oil bath was
raised, to about h^° C, and a slow stream of carbon dioxide was passed in
the side arm of the bridge and out through the separatory funnel into a
venting tube made of 25-millime'ter glass tubing. Reaction between
methyl iodide and. the couple was complete after 10 hours, provided that
the couple was sufficiently active. When reaction had ceased, .as shown
by the cessation of refltix, the carbon-dioxide flow was stopped, 500 ml
8 NACA IN No . 121*7
of toluene was added to the three-neck flask, and the top of the separa-
tory funnel' was fitted with a tee tube . The reflux condenser on the one-
neck flask was heated with steam, and the temperature of the oil hath
was gradually raised over a period of 2 hours to about l8o° C . This
caused the methylzinc iodide in the flask to decompose into dimethyl zinc
'and zinc iodide. The dimethyl zinc distilled across the "bridge into the
toluene in the three -neck flask. Carbon dioxide was allowed to flow
through the top of the tee while distillation of dimethyl zinc was in
After distillation of dimethyl zinc was complete, the single-neck
flask waB allowed to cool and the side arm on the bridge connected to a
gas-purification train comprising, in the order named, a wash "bottle con-
taining water, two "bottles containing 85 -percent sulfuric acid, an empty
"bottle, a "bottle containing ^0-percent potassium hydroxide, a calcium-
chloride drying tower, and a 100- "by 1.5-centimeter tube fj lied with
silica gel. After passing through. this train, the gas was led into a
condensing Bystem comprising a copper coll condenser at -10° C, a re-
ceiver at -78 C, and finally a trap at -78 C.
The flask containing toluene and dimethyl zinc was cooled to 5 C,
and 525 ml (about h.Q moles) of t-butyl chloride in 750 ml of dry toluene
was added during 5 hours. During the addition of- chloride, methene was
evolved by the reaction. After the addition of chloride was complete,
the reaction mixture was allowed to stand 15 hours. Then the bath tem-
perature was raised gradually to 50° 0, during which time more gas was
given off which was not affected by the sulfuric acid and which did not
condense in the -78 a C trap . ...
"Water was then added to the reaction mixture .through the separatory
funnel. It was necessary to exercise considerable care in this opera-
tion, since- a violent evolution of neopentane took place at this point.
This, gas was condensed in the -10° C condenser, and solidified in the
receiver. There was no discoloration of the sulfuric acid. After, about
200 ml of water had been added and the evolution of gas had subsided,
the apparatus was swept out with nitrogen.
The- resulting neopentane was transferred to a glass tube and Bealed.
The yield amounted to 164.5 grams, which is 59 percent of that theoreti-
cally possible, based on one half the amount of methyl iodide used (2
moles of methyl iodide give 1 mole of dimethyl zinc). The residue from
the dimethyl zinc, which contained zinc Iodide, was used to prepare addi-
tional methyl iodide by the method described In reference 12.
In assembling the apparatus, corkB, rather than rubber stoppers,
were used exclusively and after assembly they were coated with shellac .
In one preliminary experiment, in which rubber stoppers were used, the
product was contaminated with a material which had the odor of methyl
NACA TN No . 12^7 9
mercaptan. Where rubber tubing was necessary in making connections to
the side arm on the' "bridge," arrangeiiient was made so that a minimum of
rubber surface was exposed.
The yield reported on the first run was verified later when nine
additional runs of this preparation were- made, in which an average yield
of 65.6, percent was. obtained, m two of these runs, the couple was less
active than in the other preparations, and the product was contaminated
with methyl iodide. The presence of methyl iodide was characterized "by
a pink color which developed in the product after a few days. The yield
obtained in one run was low because a stoppage developed in the purifica-
tion train, and some material was lost through a" loosened connection.
Freezing-point measurements made on the material from three experi-
ments gave -the values -I0.61 , -l6.6l°, and -16.60 C, respectively.
These data may "be compared with the value -16.63 ±0.10° C, calculated
for the freezing point of 100 -percent-pure neopentane by Aston and
Messerly'. "(See, reference 13 . )
From 75*2 moles of ethyl magnesium chloride and 37 moles of ethyl
acetate there was prepared 3660 ml of 3-methyl-3-pentanol, which was
purified "by distillation in Column 7 ("b.p< 120° to 124° C at 76O mm).
Dehydration of this carbinol "by refluxing with 0.2-percent 3. -naphthalene
sulfonic acid .yielded a mixture of . alkenes which "boiled 65 to 71° C at
758 millimeters. This dehydration would "be expected to yield chiefly 3-
methyl-2-pentane, with a smaller amount of 2-ethyl-l-butene . No attempt
was 'made to separate the two" olefins. since both compounds yield the same
alkane" when, hydrogenated . . Hydrogenatibn of this mixture gave crude
alkane which was filtered through silica gel and distilled in. Column k
to. yield 1980 ml of material which boiled" 64.5° to 65 .5° C (uncorrected).
Redistillation in Column 1 gave- 1^20 ml of hydrocarbon made up of frac-
tions' removed while the head temperature was 63.319 to 63. 322° C (76I.I
mm Jig) and for which . n-jf° =. 1.376k to I.3765. . ;'
' . ■ 2,2-Dimethylbutane (Neohexane) . . .
The synthesis of neohexane has been reported previously: in refer-
ence k. Since then commercial neohexane has become available. Several
charges of this material were fractionated in Stills 1 and 2 . ■ From each
run, only the latter half "of the distillate consisted of material having
this properties of neohexane . The forerun contained -an -impurity of
higher refractive index and' slightly lower "boiling point. No extensive
investigation was made of this forerun, "but the most likely impurity was
cyclopentane . This fact was later substantiated "by the manufacturer.
NACA TN No. 12U7
A total of. 38 liters of 'purified neohexane .was propared "by fractionation
of 75 liters' of the commercial crude mixture in Still 11.
2 -Me thy lpent arte
About 75 liters of commercial crude neohexane was fractionated, to
prepare 38 liters of 2, 2-dimethylbutane . From the distillations of this
material, there was obtained 3320 ml of residue, which, was fractionated
in Column 2 into k6 fractions :
Refractive index, np 20
1 to 22
23 to kk
k$ to k6
58.8 to 60..2
60.2 to 60. k
I.37W to 1.3717
1.3715 to 1.3717
1.3717 to I.37IA
Fractions 35 to 37 were combined, filtered through silica gel, and used
in the determinations of physical properties of 2-methylpentane .
Investigation of Butene Alkylate
Seventy-five liters of Butene Alkylate was fractionated in Still 10.
The head temperature was measured by means of a recording thermometer of
the gas-expansion type. The reflux ratio was maintained' at about 100 to
1. Fractions of not more than 3.87 liters each were collected, the vol-
ume of the fraction depending on the time -temperature curv* . After
measurement of refractive indices,' .like fractions from different runs
were combined and refractionated in Still 2. Fractionation of the low-
est 'boiling portion from Still 10 was carried out first, then the second
lowest "boiling was added to. the residue and fractionated, and so on.
The refractive index of each fraction was measured, and a plot of refrac-
tive index versus fraction number was made. Samples represented by sin-
gle plateaus were combined and redistilled in Column 1 or 2. Several
hydrocarbons were isolated thereby, and are listed in table 3»
2 , 3-Dimethylbutane ♦ - The 2,3-dimethylbutane from Butene Alkylate
( 2213 ml) was added to 1255 ml of 2,3-dimethylbutane of approximately
the same purity from another source. The combined material was washed
with sulfuric acid, water, sodium-carbonate solution, and again with
water. • After it was dried and filtered through silica gel, it was frac-
tionated in Still 2, and gave 2300 ml of material for which
ni, 20 ■> I.37WJ to 1.37^9.
NACA TH No . 12^7 11
2 , U-Dime thylpentane . - The' 2, It-dimethyl pentane from Butene Alkylate
(26l0 ml) was refract ionated in Still 2. The fractions for which
nD ao = I.3816 to I.3817 were reserved as the best portion, and amounted
to 985 ml.
2,3-Dimethylpentane from Isooctane
Seventy-five liters of isooctane (a commercial mixture of "branched
chain hydrocarbons) was fractionated in Still 10 in the manner described
in the preceding section. Fractions which distilled "between 85 and
95° C (n© 20 - 1.3886 to 1.391*0 were combined (28,051 ml) and refraction-
ated in Still 11. Prom this distillation there was obtained 7165 ml of
hydrocarbon which boiled 89 .7° to 90.0° C (n D ao = l;39l8 to 1.3921) which
was refractionated in Still 2. The purified 2,3-dimethylpentane thereby
obtained amounted to lj-790 ml after filtration through silica gel. The
refractive index range n^ 20 ; of various fractions was l«3919i "to 1.39l9e*
. The synthesis of triptane involved two reactions: (a) the prepara-
tion of 2-chloro- 2,3-dimethylbutane, arid (b) the reaction of this chlo-
ride with, dimethyl zinc.
i 2-Chloro- 2,3-dimethylbutane .- The apparatus used was, similar to
that, described in. reference 2 for. the' preparation of ij--chloro- 2,2 ,k-
trimethylpentane . it was modified 'so that rubber stoppers were replaced
with grou nd -glass connections. The alkene used was a mixture of 2,3-
dimethyl-1-butens and 2,3-dimethyl-2-bute.ne,. which was formed by dehydra-
tion of pinac.plyL alcohol' (3,3r-dimethyl-2:;butanol).. (See reference 5.)
The original-, alkene mixture contained £. small amount, of 3,3-dimethyl-l-
butene, in. addition to the hexenes, but this hydrocarbon was removed for
use.; in .another, synthesis.. k .."'■'
In 2 hours, 1500 ml of the alkene mixture, along with excesB hydro-
gen-chloride, was passed through two chambers kept in a bath .at -78" C.
Occasionally it was riepessary to remove the. baths in. order to allow the
solidified chloride to melt. and. pass on through the apparatus. The prod-
uct, was, washed with water, with 5.-percent sodium-bicarbonate solution,
again with water, and dried with two successive portions of fresh anhy-
drous potassium carbonate. Distillation. of the resulting material in
Column 3 gave, after a forerun of unchanged alkene. 675 grams of 2-chloro-
2,3-dimethylbutane (b.p. 69 to 70° C at I90 mm Hg) .
Synthesis of triptane .- With apparatus like that used in the prepa-
ration of neopentane, dimethyl zinc was prepared from 1100 grams (7.75
NACA TN No. 12^7
moles) of methyl iodide and distilled into a 5-liter flask containing
500 ml of toluene. The flask was surrounded "by ice, and the chloride
600 grams, 5 moles) in 1000 ml of toluene was added during h hours. The
mixture was allowed to stand for 16 hours, and was then treated with
water and with dilute hydrochloric acid. The reaction product, 2060 ml,
was fractionated in Column 5 to give a small amount of methyl iodide,
some olefinic material, presumably dime thy rbutenes formed "by dehydro-
chlorination of the alkyl chloride, and 297 ml of crude triptane "boiling
at 78° to 83 C, with nj) 20 = I.3932. Two passages through silica gel
gave a product of the following properties, compared with those of high-
Refractive index, n D
Density, d 4 2 °
Freezing point, °C
Boiling point, °C
The yield of crude triptane amounted to 51 percent of the theoretical.
In subsequent experiments it was found that a large excess of alkyl
chloride offered no addvantage, a 2- to 3-percent excess giving a compara-
ble yield. The excess chloride was found to "be easily removed hy "boiling
the crude mixture with a 5- percent solution of potassium hydroxide in
In each of several experiments, the yield amounted to k6 to 52 per-
cent of crude triptane. The time allowed for addition of chloride was
varied from 3 to 8 hours, and the temperature of reaction from 0° to 30° C
without any appreciable change in yield. In one experiment, in which is'o-
octane (2,2,l|--trimethylpentane) was used as a solvent, the yield was k8
. Under the conditions of hydrochlorination, 2,3-dimethyl-l-"butene was
found to add hydrogen chloride more easily than 2,3-dimethyl-2-"butene.
The unreacted alkene which was recovered when a mixture of the two was
hydrochlorinated was found to "be practically pure 2,3-dimethyl-2-"butene.
Very clight decomposition of 2-chloro- 2,3-dimethyl"butane takes place
when it is "boiled at atmospheric pressure.
MCA. TN Ho . 12^7 ■ 13-
This octane vas prepared "by hydrogenation of the olefins" wh'ich re-'
suited from the dehydration of 2-methyl-3-ethyl-3-pentanol. The carbinol
was prepared "by the action of ethylmagnesium chloride on isobutyl iso-
To a solution containing 90 moles of ethylmagnesium chloride in 20
liters of ether was added 6335 grams (kk moles) of isobutyl isobutyrate
in 10 »5 liters of ether. The product vas dried with sodium carbonate and
distilled in Column 6. There was obtained 5680 ml of 2-methyl-3-ethyl-
3-pentanol (55° to 57° C at 1*8 ma. Eg) . Dehydration was effected "by re-
flusing the carbinol with 0.2 percent "by weight of p-naphthalene sulfonic
acid, which gave 5235 ml of crude alkene mixture, "boiling at llfc° to
119° C. Since dehydration of 2-methyl-3-ethyl-3-pentanol should yield
two alkenes: namely, 2-metbyl-3-ethyl-2-pentene (b.p. about 117° C) and
lj--methyl-3-ethyl-2-pentene (-"b.p. about il6° C), "both of which yield the
same alkane on hydrogenation, no attempt was made to separate the two.
The alkene mixture was driod with calcium chloride and distilled from so-
dium. A portion of the distillate (Ij-721 ml) was hydrogenated to the
alkane, which, after two distillations from sodium and filtration through
silica gel, amounted to U050 ml. The compound was finally fractionated
in Still 1, yielding 3300 ml of material, .which had a refractive index
constant within 0,0001.
2,3,3 -Tr ime thylpentane
This hydrocarbon resulted from the reaction "between isopropyl magne -
sium chlorido and-t-anyl chloride*
To 90 .5 moles of ieopropylmagnesium chloride in 30*9 liters of ether
solution was added 9600 grams (90 moles) of t-amyl chloride during a
period of about 12 hours. Stirring was continued until separation of
solid material prevented . adequate mixing. Then the reaction mixture was
allowed to stand 2 to 3 weeks at 15° to 20° C until no more Grignard re-
agent was present. The product was treated with ice and dilute hydro-
chloric acid and the resulting organic material distilled in Column 3«
After a forerun of ether,, isoamylene, and t-amyl chloride, there was ob-
tained M*00 ml of crude 2, 3, 3 -trime thylpentane (31-percent yield), which
"boiled 112° to 115° C. "When refractionated in Column l f the crude paraf-
fin gave 3600 ml of fractions for which nx> 2 ° = 1.^07^ to 1.1*075 • . Redis-
tillation of accumulated foreruns from several "batches gave an additional
quantity of puro material . From several runs a. total of 39 liters of
pure 2,3,3-trimethylpentane was prepared.
Early experiments on this preparation were made in which a large ex-
cess of G-rignard reagent was. assumed to "be desirable, • Trut It was found
Ik NACA TN No . 12U7
that the yield of product was actually decreased "by an excess of Grignard
reagent. For example, In one run In which 72 moles of isopropylmagneeium
chloride was allowed to react with 57 moles of t-amyl chloride, the yield
of 2,3,3-trlmethylpentane was only 21 percent,
2,2,3-Trlmetbylpentane and 2,3,^-Trlmethylpentane
By fractionation of several cuts of alkylate mixtures, 38.6 liters
of 2,2,3-trimethylpentane and 37,9 liters of 2,3,^-trimethylpentane were
prepared. The source materials were alkylates, hydro-codimers, and iso-
octanes whioh had accumulated at the laboratory. These materials totaled
approximately 85 gallons. Some of them were partially fractionated, some
were "as received."
The unresolved alkylates and residues were roughly fractionated In
Stills 10 and 11 into concentrates rich in 2,2,3-trimethylpentane and
2,3,*i--trimethylpentane. These concentrates were redistilled In Column 11.
Most of the material was obtained by these distillations. Foreruns, in-
termediates, and afterruns were again fractionated in Stills 1 and 2.
From a total of kf distillations there were obtained 38*610 ml (at 25° c)
of 2,2,3-trimethylpentane (nu so = l.t!-026 to 1. 1*029) and 37,955 ml (at
25° C) of 2,3,^-trimethylpentane (n D 20 = lJtOlU to 1.1*0^5). Physical
"constants of the two compounds were measured, and agreed well with those
measured on the pure materials, as reported in references h and 5*
The presence of 2,2,5-trimethylhexane in' isooctane residue was re-
ported "by Brooks, Cleaton, and Carter in 1937 • (See reference 1.) By
distillation of an additional 76 liters of this material in Still 10, a
concentrate rich in this nonane was obtained. This concentrate (1*525 ml>
b.p. 123° to 125° C, np 20 m I.399 to 1.U00) was refractionated in Still
1. There was obtained 2005 ml of 2,2,5-trImethylhexane with a refractive-
Index range of 1.3995 to I.3996.
2,3,5 -Trime thylhexane
• This nonane was prepared by hydrogenating 2,3,5-ta , imethyl-2-hexena-,
which resulted from the reaction of isopropylmagnesium chloride on 1-
chlbro-2,3-dimethyl-2-butene. There was also formed a small amount of
2,3,3,^-tetramethyl-l-pentene In this reaction.
. 2, 3-Dimethyl-l f 3 -butadiene . - Plnacol hydrate, prepared by the method
of reference 5, was dehydrated to anhydrous pihacol by distillation in
Columns k to 7. These distillations were carried out at atmospheric
NACA-'-TN No . 12^7
Pre-ssure'untii'the head" temperature reached.' 122° -0-, when, the pressure was
■reduced to 80 millimeters" of mercury. At: this pressure- the .anhydrous
pinacol distilled at -111° to 11^° C". •: • : - ■'■«-"
lii' order to ■ determine the optimum conditions for conversion of the
glycol to 2,3-&imethyl-i,3~'butadiene, a series of- test runs were made.
The results are "shown in the following table:-
DEHYDRATION OF PUTACOL TO 2,3>DIMETHn3UTADIE3SE-l,3
■ .- ■ AKD.PINACOLONE (3,3-I>IMETHyL-2rBOTAlSrONE) ■
■ > (gm)
Yield (percent) of -
1.5 grams' ^8-percent hydro -
5 .0 grams p -naphthalene sul-
■ fonic .acid
5 .0 -grams p- toluene : sulfonic
' acid : :.■.■■■. . i
7*0 grams aniline hydro-
In -thsse experiments, the pinacol was refluxed, with .-the .catalyst in Col-
umns 5 or 7» The product of each run was. washed, dried, and. distilled in
Column 6 for analysis ■. ■ From the results . of . .these experiments, it was
"concluded that -li-8-percent hydjsoTsromic acid .was ;,the- he.st catalyst of those
tried for this dehydration. ; By dehydrating sever^. "batches of pinacol
(.2 .5 to. 3 .0 • kg per hatch) ,- 17 A .liters .of 2, 3.-*dimethyl-i,.3-.hutadiene was
propared which "boiled 68.5 to 71-.5.° a-b 75? mil-lime ters...-
* ■•■•■•■ ■l^Chloro-2 . 3rdtmethyl-2-butene .- ■ The addition of hydrogen chloride
to: 2,3*&imethylT&,3-hu.tadiene. was accomplished -in the apparatus described
in -reference -2* .The reaction chambers- were kept at. -30° C, and dry hy-
drogen chloride and alk&diene added simultaneously , The daily output of
the apparatus was 1.0 to 1.5 liters of chloride. The product was froed
of dissolved hydrogen chloride by aeration with carbon dioxide and stored
over sodium carbonate. Distillation analysis showed that the reaction
was practically quantitative. The product used for further synthesis
foiled at 32° C at lj-5 millimeters of mercury.
16 NACA TN No . 12^7
2, 3,3-Trimethyl-2-hexene .- To an ether solution of 62 mole's of led-'
propylmagnesium chloride was added 7.32 kilograms of l-chloro-2,3-dimethyl-
2-butene. The reaction mixture 'became very viscous, and it was necessary
to add more ether at intervals* The reaction was worked up after k days
and the organic material was dried, the ether removed, and the crude res-
idue distilled through Column 3 (b.p, 70° to 71° C at 90 mm,
np 20 «» 1A299). Although there was no appreciable forerun, a large amount
of high-boiling material (175° to 200° C) was present. This material was
not identified, hut is presumed to he polymers (dimers and trimers) of
the alkadiene formed under the influence of the Grignard reagent*
The crude 2,3,5-trimethyl-2-hexene contained a considerable quantity
of chloride, .the greater part of which was removed by boiling with alco-
holic potassium hydroxide. Hydrogenation of the crude alkene gave 2,3,5-
trimethylhexane, which was filtered through silica gel and distilled in
Column 3 • From 2500 ml of material, there were obtained 900 ml which
boiled 131-.9 P C (nr> 20 = 1.1&60 to l.k06l) and 50 ml of a hydrocarbon
which boiled l4l*9° C (n^ 20 ■ 1.U218) . The latter was identified as
2,3,3j**--tetramethylpentane by comparison with a sample prepared in another
manner. A residue of about 1 liter which boiled above I65 C resulted
from this distillation. This residue was probably formed by the action
of potassium hydroxide or hydrogenation catalyst on the unsaturated halide
which was present in the crude olefin. Obviously, most of the Grignard
reagent was. dissipated in side reactions rather than by coupling with -the
chloride in the expected manner. This tendency could possibly have been ■
decreased by carrying out the reaction in a more dilute solution.
This preparation was made in I939 at the suggestion of Dr. C. E.
Boord of Ohio State University. The goal was the preparation of 2,3,5*
trimethylhexane and 2,3,3,U-tetramethylpentane. The reaction yielded
about eighteen parts of the former to one part of the latter. These two
hydrocarbons probably resulted from the action of the Grignard reagent on
two isomers of 2,3-dimethylchlorobutene. These two isomers probably were '
l-chloro-2,3-dimethyl-2-butene, formed by 1,4 addition of hydrogen chlo-
ride to the diolefin, and 3-chloro-2,3-dimethyl-l-butene, formed by 1,2
addition. The former chloride would be expected to react with isopropyl-
magnesium chloride to give 2,3,5-trimethyl-2-hexene, and the latter chlo-
ride to to give 2,3,3,^-tetramethyl-l-pentene.
E. T. Cline has made a study of this reaction (reference 14), in
which hydrogen bromide, rather than hydrogen chloride, was used. He ob-
tained a ratio of alkenes of 1.6 parts of 2,3,5-trimethyl-2-hexene to 1
part of 2,3,3,'4-tetramethyl-lrpentene..
NACA TN Ub.' 12U7 17
■ In 1937, Brooks, Cleaton, and Carter (reference l) isolated an un-
known nonane from the residue obtained in the distillation of isooctan©
(2,2,^-trimethylpentane), which was tentatively identified as 2,2,k~
trimethylhexane . In order to establish the identity of this hydrocarbon.
a sample of 2, 2, ^-trimethylhexane was prepared, and a comparison of phys-
ical properties made.
Diisobutylene was oxidized by sodium dichromate, as described in
reference 15 by Whitmore, Homeyer, and Trent, to give trimethylacetic
acid and l4-,lt--dimethyl-2-pentanone (methylneopentyl ketone) . The oxida-
tion of diisobutylene isomers is diBcussed more fully in later sections.
To 7.0 moles of ethylmagnesium chloride in l^O ml of ether solution
was added 7^2 grams (6.5. moles) of lt,^-dimethyl-2-pentanone (b.p. 12U° C
at 76O mm Hg, nj) 2 ° = l.li038) in 800 ml of dry ether. The reaction mixture
was allowed to Btand at xoom temperature for 35 hours, refluxed for 6
hours, and then worked up in the standard manner. The organic material
was washed, dried, and distilled in Column k. In. addition to ether and
recovered ketone, lK>9 grams (2.9 moles) of 3,5,5-trimethyl-3-hexanol and
Bk grains (0 .6* mole) of nonenes resulting from premature dehydration of
the carbinbl were obtained. The purified carbinol was dehydrated by heat-
ing with P-naphthalene sulfonic acid (1 gram) to give a mixture of alkenes
which boiled 127° to 132° C. The yield was 335 grams (91 percent). This
alkene mixture has been analyzed by Whitmore and Cook ( reference 16) who
found by ozonolysis that it contained approximately three parts of 3,5,5-
trimethyl-2-hexene, one part of 2-ethyl-li-,4-dimethyl-l-pentene, and a
trace of 3,5,5-trimethyl-3-hexene. All these compounds give the same
alkane when hydrogenated, so no attempt was made to separate them.
' The alkenes were hydrogenated, and the product filtered through
silica gel and distilled in Column 5. ■ The middle JO percent of the dis-
tillate, which distilled at a constant temperature, was redistilled v in
the same column, the middle 25 percent of the distillate from the latter
distillation was used in the measurement of physical properties. The
properties of the synthetic material are given in table 2 and are compared
in the following table with the properties of 2, 2, h~ trimethylhexane, which
was isolated. by the present authors. The identity of the two is proved
by data on the freezing point- of the 50 :50 mixture .
NACA TN No . 1247
2, 2, 4- trlmethylhexane
Boiling point at 760 mm Hg, °C
Change in "boiling point with
pressure, °c/mm Hg
Freezing point, °C
-123 .4 (mp)
Freezing point of mixture, °C
Befractive index, nj) 20
Density, gm/ml, d 2 °
^he published density, 0.7048 (reference l) of the material Isolated
from isooctano residue was in error. A recalculation of the original data
gave O.7153, redetermination gave 0.715k.
The synthesis of 2,2-dimethyl-3-ethylpentane was carried out in the
following steps: (a) Reaction of t-butylmagne slum chloride with carbon
dioxide to give the Grignard complex of trimethylacetlc acid, (Td) reac-
tion of this complex with ethylmagneslum chloride to produce 2,2-dimethyl-
3-ethyl-3-pentanol, (c) dehydration of the carblnol to 4,4-dimethyl-3-
ethyl-2-pentene, and (d) hydrogenation of the olefin to 2,2-dimethyl-3-
To 50.2 moles of t-butylmagnesium chloride in 18 liters of ether,
cooled to 5° C, was added 3 kilograms of solid carbon dioxide in small
pieces while the' reaction mixture was being stirred. Stirring was con-
tinued while the mixture came to room temperature and while it was heated
to reflux for 2 hours. It was then cooled and 104 moles of ethylmagne-
sium chloride in 20 liters of ether was added slowly. After addition was
complete, the mixture was stirred for 6 hours and allowed to stand at
room temperature for 2 days. The product was distilled In Column 6.
From this distillation was obtained 3U85 grams (48.2 percent yield) of
cartonol (la .p. 90 to 95° C at 50 mm Hg,. 151° to 176 C' at 756 mm Hg,
n D so ■ 1.4417, d 2 ° =0.851). The carhinol was dehydrated "by heating
NACA «HT No. 12^7
with 3 -naphthalene sulfonic acid to give 3600 ml of alkene. Fraction-
ation of the crude alkene in Column 5 gave 2680 ml of .purified k,h-
dlmethyl-3-ethyl-2-pentene* .The alkene was hydrogenated, and the product
filtered through silica gel and distilled in Column 1. From this distil-
lation 3.650 ml of •constant-'boiling 2,2-dimethyl-3-ethylpentane
(RD 20 ■ 1.U1225 to 1A1230) was obtained.
2, ^-Dimethyl- 3-lthylpentane
Preparation, of 2,U-dimethyl-3-ethylpentane was accomplished by hydro-
■'genation of the alkenes which resulted from the dehydration of 2,k-
; -dimethyl- 3-ethyl-3-pentanol". The carbinol resulted from the action of
ethylmagnesium chloride on 2, ^-dimethyl- 3 -psntanone (diisopropyl ketone).
To 76.2. .moles of ethylmagnesium chloride was added 75 moles of ' 2, it-
dimethyl- 3-pentanone during 2 days. The product was recovered "by addi-
tion of ice and ammonium chloride to the. reaction mixture, and "by subse-
quent distillation gave 5650 grams (52.3 percent) of '2,^-dimethyl-3-ethyl-
3-pentanol. A pure sample was obtained "by redistillation of the "best
portion of the crude.
The carhinol- was dehydrated with 3 -naphthalene sulfonic acid to give
6110 ml of crude alkene mixture. A charge of 2 liters of the dehydration
product was fractionated in Column 5 for analysis. The individual olefins
were recovered in the ratio of 77 percent of the lower-boiling 2,k-
dimethyl- 3- ethyl- 2-pentene to 23 percent of the higher-boiling li-methyl-
3-isopropyl-2-pentene . A sample of each of these Isomers was redistilled
for determination of physical constants . The values obtained were :
2, ii-Dimethyl- '
Boiling point at 760 am Hg, °C
Refractive index, n.j) ao
Density,' d 20
d a5 .
Hydrogenation of samples of "both alkenes yielded the same alkane.
The alkene mixture (b.p. 128° to lUo° C) was hydrogenated and the result-
ing product distilled, in Column h. ' The -portion' "boiling I36 to-139° C
was filtered through silica gel and refractionate'd in Column 1.
20 WACA TN No . 12^7
In 19^5 "the preparation was repeated on a somewhat larger scale.
For this preparation, 2, ^-dimethyl- 3-pentanone was fractionated' in Still
11. Only the purest fractions obtained (Id .p. 12ij-.6° to 12*4- .7° C,
njj 20 = J.Uq'15 to 1.^017} were used in the subsequent synthesis.- The. car-
ls inol was, the product of ' reaction- of the-Grignard reagent prepared from
260 moles of ethyl chloride with 223 moles of redistilled ketone. .The
reaction product was -distilled in Column 21 .'until the head temperature
was 130° C. A sample (1660 grams) of the residue' was< distilled in Column
k. From this distillation. there 'were obtained 1130 grams of pure carbi-
nol (2,U-dimethyl-3-ethyl-3-pentanol, b.p. 9^.5° to 95 .0° C at kj mm Hg)
and about 200 grams of less pure material. A sample from the middle cut
of this distillation .was reserved for.-physicaT constants measurements.
: The rest of the undi stilled residue was dehydrated, with; sfrrnaphththalreie
sulfonic acid, and- the dehydration products were. washed/ driedjo and- dis-
tilled in Column 11.. Analysis of the distillation curve showed the- pres-
ence of 77 volume percent (13 A' liters) -of lower-toiling- olef.in>-,and 23
volume 'percent (U.O liters) of the higher-boiling isomer. In this distil-
lation a "best sample from each .of the. plateaus was reserved, and redis-
tilled in Column 17* for physical-constants measurements. Hydrogenation
of- the- olefins was carried out as previously described. The paraffin was
fractionated in Columns 17, 18, 19, and 20. There was obtained lljSoo ml
of pure hydrocarbon for engine tests. Physical constants of materials
synthesized in this later preparation are given in table 2. '
2 , 2 , 3 - 3-Te trame thylpent ane < Te trane ) 1
The synthesis of 2,2,3,3-tetramethylpentane (a new compound desig-
nated- tetrahe) was first accomplished in 19^0 (October-December). : The re-
daction involved (a) preparation of 2,3,3-trimethyl-2-butanol ( trlptanol)
'from 3,3-diirtethyl-2-but»aiione (-pinacolone) and methylmagnesium bromide,
(b) reaction of this carlo inol with hydrochloric .acid to. give 2rchloro-
: 2,3,3 -trimetii.ylbutane (triptyl chloride), and (c) reaction of the chlo-
' ride with ethylmagnesium chloride to give the nonane and 2, 3,3-trimethyl-
• 1-butene (triptene) .
From 82 mplee of pinacolone and 6% moles of methylmagnesium bromide,
56 ;-5 moles of 2,3,3-trimethyl-2-butanol was prepared. This carbinol was
dissolved in ether, and the solution shaken with several portions .of con-
centrated hydrochloric acid. Samples of the ether solution were removed
periodically. The sublimation point of the crude chloride from these
samples- rose to 131° to 133° C . Recrystallized chloride was found to sub-
lime at 133° C. The chloride solution was washed, dried, .and added to 115
moles of ethylmagnesium chloride. The mixture was stirred for 3 hours and
then allowed to stand for .h weeks at room temperature .
^•Compounds designated with asterisks -are. believed -to be new compounds.
1 . .' v *
NACA TN No. 12it7 21
After the reaction mixture vas worked up, the organic material was
distilled in Column 6, and yielded 2100 ml of recovered triptene (tri-
methylbutene) and 1900 ml of crude 2,2,3,3-tetramethylpentane, which was
contaminated "by a considerable amount of triptanol. The carbinol was
filtered off as the hydrate, and the filtrate dried and filtered through
silica gel. 'The volume of nonane recovered was 1250 ml, which represents
a yield of 9 percent, based on the original pinacolone. Distillation of
this material in Column k gave IO87 ml of hydrocarbon which was collected
at 88.6° to 88.7 C at 159 millimeters of mercury. A portion of this ma-
terial was recrystallized repeatedly, until the refractive index and
freezing point. were unchanged by further crystallization. Physical con-
stants were measured on this. sample. A second run of this preparation
was made in March I9UJL/ in which' recrystallized triptyl chlaride was
reacted with an equimolar quantity of the Grignard reagent. In this case
the yield was increased to 22 percent, "based on the chloride.
Procurement of 10 gallons of this hydrocarbon was undertaken in
I9IH. Part of this (2.9 gal) was prepared at Ohio State University the
rest was prepared in these laboratories. This large-scale preparation
was carried out by a modification of the technique developed at Ohio
State University. The chloride was added to the Grignard reagent in
eight equal portions, in 8 successive days, while the reaction mixture
was kept at 35° C.
An improved method was devised for the preparation of the large quan-
tities of triptyl chloride necessary for this synthesis. The equipment
consisted of three reactors, made from 30 -inch lengths of 12- inch pipe,
closed at both ends with companion and blind flanges. One end of each re-
actor was fitted with a small steel valve (l/h- in.) . These reactors were
refrigerated (-30° C) and were connected to a manifold through which hy-
drogen chloride could be admitted to eaGh. The reactors were charged with
triptene in wide -mouth bottles. The flanges of .the reactors were secured
by bolts and the reactors were allowed to stand until cold. Hydrogen
chloride was then admitted until the pressure was 100 to 120 psi. The
pressure gradually fell as the gas reacted until the pressure was about
50 to 60 psi. . Then the process was repeated until there was no, appreci-
able change in pressure during an hour. The excess gas was released, the
system purged with dry air, and the product removed. The yield was prac-
tically quantitative . The product was uncolored and contained a. small
amount of excess hydrogen chloride. This excess was converted to alkyl
chloride by adding a small amount of olefin to each jar and allowing to
stand until reacted. By means of this technique, 20 to 35 liters of
triptene was converted to the chloride in 1 working day.
To 300 moles of ethyl magnesium chloride there was added 360 moles of
triptyl chloride in eight equal portions during 8 days. During this time,
the reaction mixture was heated to reflux temperature and stirred. At the
end of 2 to h additional days, when all the Grignard reagent had reacted,
22 NACA Tff No. 12Vf
the mixture was worked tip with ice and hydrochloric acid and washed four
times with water. Distillation of the ether, and of most of the triptene
was carried out from the reaction kettle. The distillate was dried and
redistilled in Column 12 or 13 for recovery of triptene •
The residue in the reaction kettle was "boiled with sodium propylate
in propyl alcohol until the product was subetatially free of chloride.
After the product was washed,, it was steam distilled, and the distillate
dried end "boiled with alcoholic silver nitrate to remove the last traces
of chloride. Then the product was filtered, washed several times, dried,
and distilled in Columns 11, 18, 19, and 20, Prom two runs as doscribed,
which were worked up together, there was. obtained 1^.92 kilograms ( 116.6
moles) of tetrane which was 99*6 mole percent pure. This represents a
yield of 19 .h percent. A total of 21.7 kilograms was prepared by this
2,2,3,t-Tetramethylpentane and 2,3,3,U-Tetramethylpentane
The first preparation of these two nonanes was accomplished in June
19^1 lay hydrogenation of the alkenes (reference 17) formed "by the dehydra-
tion of 2,2,3,U~tetramethyl-3-pentanol. The carbinol wab prepared by the
reaction between methylmagnesium bromide and 2,2,U-trimethyl-3-pentanone.
This ketone was the result of oxidation of 2,2,l4--trimethyl-3-pentanol,
one of the products resulting from the action of t-butylmagnesium chloride
on isobutyraldehyde .
The method of reference 17 was used to prepare 2,2,^-trimethyl-3-
pentanol. To 55 moles of t-butylmagnesium chloride was added 3960 grams
(55 moles) of isobutyraldehyde. Distillation of the organic reaction
products gave U290 grams (33 moles, 60-percent yield) of 2,2,t»-trimethyl-
3-pentanol. The carbinol was oxidized to pentamethylacetone (2,2,1*--
trimethyl-3-pentanone) with potassium dichromate and sulfuric acid, by
method of Faworsky. (See reference 18.) From 32 moles of carbinol,
there was obtainod 3150 grams (2^.6 moles, 77-percent yield) of ketone,
which was distilled in Column 5.
The 2,2,*t--trimethyl-3-pentanone (2k. 6 moles) in 6 liters of ether
was reacted with 26 moles of methylmagnesium bromide, and the product dis-
tilled in Column 5 until the temperature reached 1^3° C. At this point
dehydration of the carbinol was beginning to take place, so the distilla-
tion was interrupted, and the clear, slightly yellow residue (2950 ml)
was dehydrated with (5 -naphthalene sulfonic acid.
: From the dehydration there resulted 2lH0 ml of alkene mixture, which
was dried and distilled in Column 3. The following fractions were ob-
NACA TN No . 18^7
91 to 119
119 to 12k
12U to 129
130 to 135
2,3, 3, ^-Tetramethyl-
Fractions 2, *3, and k represent a combined yield of alkenes of 15 .9
moles (65 percent, based on 2,2,^-trimethyl-3-pentanone) . Samples from
the middle of the plateaus represented "by fractions 2 and h were reserved
for physical-constants measurements. No attempt was made to isolate
2,3,li,lt-t6tramethyl-2-pentene, a very small quantity of which was found
"by Vhitmore and Laughlin in ' reference 17 •
The alkene fraction which distilled 119° to 12lt-° C was hydrogenated,
and the product was filtered through silica gel and distilled in "Column
3. There was obtained 1G7Q ml of hydrocarbon which "boiled 133.7° to
13^.1° C, nj) 20 (uncorrected) = iJklhJ to 1JH50. ("Uncorrected" means
no correction for possible instrument error.) Redistillation of this ma-
terial gave 930 ml collected at 133 .8° C. Physical constants were "deter-
mined on a Bample from the. center of this fraction.
The alkene fraction k was treated in like manner, ' and yielded 3^7 ml
of jrialterial 'Qollected at 1^2° C (uncorrected), fractions .'of which showed
a, refractive -index range np 20 (uncorrected) of I.U219 to l.lj-220. A.,
sample from 'this distillation was reserved/for" determination' of physical
constants. . All .intermediate fractions, foreruns, residues, and material
eluted from silica gel were hydrpgenated and distilled in Column 8, In
this way, there were obtained an additional 200 ml of 2,-2,3,Vtetramethyl-
pentane and lk-5 'mi of 2,3,3,lt-tetemiethylpentane,
Tests on these- two hydrocarbons demonstrated the advisability of pre-
paring larger quantities. Consequently, 10 gallons of each was synthe-
sized at Pennsylvania State College . These hydrocarbons were purified in
these laboratories for engine tests by 'distillation in Column- 1. New
pure samples f.or measurement of physical • constants ' were obtained concur-
rently. The. improved data are given in table 2»
2>+ NAOA TN No. 12*1-7
Dimethyl-Zinc Synthesis of Three Tetramethylpentenes
An olefin co-polymer fraction containing 3, 1 *, t '--trimethyl-2-pentene
and 2,3,^-trimethyl-2-pentene, was reacted with dry hydrogen chloride un-
til about 60 percent of the oiofin waB converted to chloride. This
chloride- olefin mixture was treated with dimethyl zinc in a solvent of
hydrogenated co-dimer, which contained 2,2,3- and 2,3,^-trimethylpentanes.
The resultant product was hydrogenated to a mixture of hydrocarbons, all
known to have superior characteristics. This study led'tft-'the^synibheses
of these compounds in a pure state by this method.
Secondary and tertiary butyl alcohols were co-polymerized in the
presence of sulfuric acid in the manner described in reference 19« A
portion of the product was analyzed by distillation in Column 1 and was
found to contain the diisobutylenes, 2,^,^-trimethyl-l- and -2-pentenes
(25 percent), 3,lj-,lj-trimethyl-2-pentene (23 percent), 2,3,U~trimethyl-2~
pentene (37 percent), and higher-boiling material (15 percent). The rest
of the olefin mixture was routihly separated by distillation in Column 5»
The fractions which boiled 107° to 120° C amounted to 97^0 grams and con-
sisted of 2,3,4-trimethyl-2-peritene and 3,^,^-trimethyl-2-pentene aB ma.'Jor
components. Part of this fraction (6300 grams) was fractionated in Col-
umn 2. By this distillation there were obtained' 1150 grams of 3,^,^-
trimethyl-2-pentene (nj> 20 - IA23O, np 25 « 1.1+205, d 2 ° = 0.7392,
d 25 = 0.7350, b.p. 112.1° to 112.8° C.) .and 1865 grams of 2,3,^-trimethyl-
2-pentene (n D 20 » 1A275, nr 25 = IA250, d 2 ° = ,0.7^, d S5 - 0.7391; h.p.
116. 3° to. 116.'5° C).
These two alkenes were reacted separately with hydrogen chloride at
-6o° C in an apparatus described in reference 2 until approximately 60
percont of the alkene had been converted ..to alfcyl chloride . The products
were washed, .dried, and fractionated in .Columen 3» In this way, 7l6 grams
of constant-boiling 3-chloro-2,2,3-trimethylpentane was obtained from the
3,.U,^-trimethyl-2-pentene. The chloride from 2,3,if--trimethyl-2-pe>ntene
(lA.10 grams) was probably a mixture of 2-chloro-2,3,t-trimethylpentane
and 3-chloro-2,3>^-trimethylpentane. Since these two chlorides were ex-
pected to yield two different nonanes (by reaction with dimethyl zinc),
with boiling points differing by about 8° C, no attempt was made to sepa-
rate the chloride mixture. Physical , constants measured on the chlorides
are. included in table 2.
2,2,3. 3-Tetramsthylpentane . - In the apparatus, and by the technique
described previously, 4- .15 moles (6lk grams), of 3-chloro-2.2,3-trimothyl-
pentahe in 700 ml of isooctane (2,2,4-trimethylpentane, S-k reference
fuel) was allowed to react with the dimethyl zinc from 7.75 moles' of
methyl iodide. The dimethyl zinc was in a solution with 500 ml of iso-
ootane. The bath temperature for the reaction was 7° C. The product was
boiled for 2 hours with 5-percent potassium hydroxide in alcohol, washed,
and fractionated in Column k. This distillation gave:
NACA TN No . 1247
Refractive index, np
96 to 100
100 to 110
110 to 116
116 to 138.6
138.6 to 1U0.3
1.4195 to 1.4225
Distillation, of the residue was continued in Still 8 and gave :
8 j 140.3
9 (Residue) >l40.3
" Fraction 1 was. recovered solvent. Alkene "by-products of the reac-
tion, formed "by dehydrochlorination of the alkyl chloride, were contained
.in fractions 2 to 5» By the low refractive indices of these fractions,
it is indicated that this material consisted mostly of 3>4,4-trimetbyl-
2-pentene. The yield of 2,2,3,3-tetramethylpentane (fractions 6, 7, • and
8) amounted to 37 «7 -percent "based on alkyl chloride. ' Fraction 7 > .after
filtration through silica gel', had the following properties: freezing
point, -11. 85 C, toiling point, 140.20° to 140.23° C at 760 millimeters
'of mercury,- refractive index, n^ 20 = 1.4233, np 25 = 1.4211j density,
d 20 ss O.7565, d 35 -sb 0.7527. " It may "be seen that the product was of high
purity whon these properties are compared with those of the- pure sample,
as listed in tahle 2 . "The freezing point indicates a purity of about
99.5 mole percent. . r
2, 2, 3, 4-. 'and 2,3, 3 ,4-Tetramethylpentanes .- By use- of the same proced-
ure as. described, two runs were made in which a total of 8.35 moles of
the mixture of 2-, arid 3-chloro-2 jr 3,4-trimettiyipentanes was reacted, at
10° C,with the dimethyl zinc from 15»5 moles of methyl iodide. The com-
bined products were refluxed with alcoholic potassium -hydroxide, washed,
dried, and distilled in Column 4. This operation gave:
naca'tn No. 121+7
Refractive index, nj) 20
3 to h
6 to 8
95 to 100
100 to 115
115 to 119
119 to 130
130.0 to 133.5
' 133.5 tb 13U.O
13U to 1U0
' 1. 1V269 to 1. 1+267
I.I+I58 to 1.1+150
The residue was distilled in Still 8, and gave:
lUo.O to 1*1-1.5
11+1.5 to 11+2.0
11+2.0 to 1I+3.O
li+3 to 165
Fraction 1 vas recovered isooctane; fractions 3 to 1+ were alkene "by-
products, indicated to "be mostly 2,3,l+-trimethyl-2-pentene "by the refrac-
tive indices. The total yield of tetramethylpentanes (fractions 6 to ll+)
amounted to 30 percent, "based on alkyl chloride. These tetramethylpen-
tanes consisted of about 71 percent of 2j2,3,l+-tetramethylpentane and
a"bout 29 percent of 2,3,3,l+-tetramethylpentane.
Fraction 9, after filtration through silica gel, had the following
properties: freezing point, -122 .5!+° C, toiling point, 133.3° to 133.1+ C
at 760 millimeters of mercury, refraotive index, njj 2 ° » 1.1+11+8,
nu 25 » 1. 1+127 j density, d £ ° « 0.7397, d 25 - 0.735*'. These values are in
agreement with those reported for the pure 2,2,3,5-tetramethylpentane in
table 2. Fraction 12 was filtered through silica gel, and the eluent used
for measurement of physical properties. These properties were found to
"be : tolling point, lf+1 .3° to l&l .1+° C at 760 millimeters of mercury,- re-
fractive index, nu 20 = 1.1+217, n D 25 = I.I+I96, density, d 20 =» 0.75^5,
d 25 s 0.7512. These data agree with those reported for purer 2,3,3,k-
tetramothylpentane in table 2.
A tetramothylpentane, assumed to "be 2,3,3,l+-tetramethylpentane, was
prepared "by Dinerstein (reference 20) in 19^0, "by action of dimethyl zinc
on 3-chloro-2,3,l+-trimethylpentane. Later work "by Enyeart (reference 21
and "by the present authors shows that the hydrocarbon described by
Dinerstein was 2,2,3,l+-tetramethylpentane.
NACA TN No. 12lf-T 27
*2, ^-I)imethl-3-lBopropylpentane (Trilsopropylmethane)
The recent preparations of triisonropylcarbinol "by the action of
isopropyl lithium on 2,l*--dimethyl-3-pentanone (diisopropyl ketone) (see
reference 22) and "by the action of isopropyl chloride on diisopropyl
ketone in the presence of sodium (see reference 23) have made available
a method for synthesizing .triisopropylmethane (2,J+Tdim6thyl-3-ieopropyl-:
pentane). A quantity of this compound has "been prepared by the use of
Preliminary work on this reaction was performed in several small-
scale experiments, in each of which 10 gram atoms of lithium, 6.5 moles ■
of isopropyl chloride, 5»^ moles of diisopropyl ketone, and 2000 ml of
solvent were used. During this study, it was found that technical 2,2,H-
trimethylpentane (isooctane) served admirably as a sol-vent when its iise
was augmented "by efficient stirring and external cooling of the reaction
mixture. Kb preliminary purification of the solvent was necessary and
the hazards accompanying its use are much less than those of petroleum
ether, used "by the origin«il investigators. (See reference 22.)
The preparation of the considerable quantities of finely divided
lithium required was expedited "by the use of a small laboratory rolling
mill. While the lithium was "being worked in the mill it was, lubricated
and coated with a mixture of 8o-percent isooctane and 20-percent light
mineral oil applied "by means of an oil can. This technique tended to
prevent the lithium from sticking to the rolls and also prevented exces-
sive oxide formation. The rolled pieces, about 0.003 inch thick, were
cut into ribbons and then into squares in large shallow pan under iso-
The yields in all the preliminary runs amounted to 18 to^ 22 percent
of carbinol. Wo appreciable change in yield was experienced when the
reaction between isopropyl lithium and diisopropyl ketone w*,s carried out
at 99° C, the temperature of boiling isooctane, rather, than- ai 35° C,
the temperature used by the original investigators.
. -After the technique of 'handling the reaction had been sufficiently
developed, a large run was- carried out in the 50-gallon stainless-steel
kettle. Tha total' quantity of reactants used was: 159 gram atoms (1.10
kg) cf lithium, 115 moles (9 .03 kg) of isopropyl chloride, 80 moles (9.13
kg) of diisopropyl ketone, and 55 liters- of isooctane. The quantity of
isopropyl chloride was relatively larger than that used by the original
investigators in order that a minimum amount of lithium be left unreacted
and that any loss occurring through the reflux condenser be replenished.
The diisopropyl ketone was constant-boiling material obtained by redis-
tillation of the commercial product in Still 11.
28 NACA TN Ho. 12^7
The kettle was flushed with nitrogen and charged with 31 liters of
iaooctane. A"bout half the lithium was added and the reaction started "by
the addition of 1 liter of isopi-opyl chloride in 1 liter of isooctane,
and "by warming the (Jacket to 35° C . The remainder of- the lithium was
added in three additional charges during the next 2g- days. During the
first 3 days, a mixture of the remainder of the isopropyl chloride in an
equal volume of isooctane was added in four charges,
A solution of di isopropyl ketone in 11 ,k liters of isooctane was
added during 8 hours, while the reaction temperature was held at k^° to
60° C. After addition was complete, the mixture was warmed and stirred
for 5 hours, after which it was cooled. Decomposition of the reaction
mixture was effected "by the addition of 25 pounds of cracked ice, fol-
lowed lay a solution of 11 pounds of ammonium chloride in 5 gallons of
water. The aqueous layer was removed, and the organic layer washed five
times, each time with 3 to 5 gallons of water, after which it was with-
drawn and dried overnight with potassium carbonate.
Fractionation of the product in Column 6 gave: recovered isooctane,
diisopropyl ketone, toiling point 121° to 126° C, 2355 grains > intermediate
fractions, 2kO grams; and triisopropylcarMnol, "boiling point 10U° to
110° C at 50 to 55 millimeters of mercury, 2576 grams. This represents a
yield of 20.4 percent "based on the diisopropyl ketone added. A prrt of
the triisopropylcarMnol was redistilled, and a pure sample col.^.cfced from
the middle of this distillation for the measurement of physical constants.
The carMnol ' was dehydrabed "by distillation from anhydrous copper
sulfate. From 16 -moles of triisopropylcarMnol, Ik.k moles (90 percent)
of crude 2,lt-dimethyl-3-isopropyl-2-pentene, was obtained. Water recovery
amounted to 80 percent. The crude olefin was dried over calcium chloride
and distilled in Column 6, from which 1372 grams of material, which toiled
153 .2° to 153.6° C at 756 to 759 millimeters of mercury, n^ = 1A368
to 1A371 (all values uncorrected), was collected. A sample was removed
from the middle of the distillation for the measurement of physical con-
The olefin was hydrogenated, and distilled in Column 6, and gave
1100 grams (80 percent) of constant-hoiling material, "boiling point
156 .5° C at 7^9 millimeters of mercury, n D £ °= l.ii-234 to l.lj-236* (all val-
ues uncorrected) . This material contained a trace of olefin which was
removed "by repeated filtration through silica gel. Befractionation under
reduced pressure afforded the means of obtaining a pure sample for
NACA IN Wo. 12^7 29
2*2.3,3' *<-Pent ame thylpentane . - The first preparation of 2,2,3,3, U-
pentamethylpentanewas carried out in February X9^ "by the reaction
"between 2-chloro-2, 3,3-trimethylbutane and isopropylmagneslum chloride.
To 30.5 moles of isopropyl magnesium chloride in 10.53 liters of
ether solution, there was added, at room temperature, 26. h moles of 2-
chloro-2,3,3-trimethylbutane (sublimation point 132.7° to 13lj-° C) in 3.5
liters of ether. After standing for 3 weeks at 15° to 20° C, the reac-
tion mixture was worked" up in the usual manner* The product, distilled
in Column': 6 ; gave:
1^.8 moles of 2,3,3-trimethyl-l-"butene, formed "by dehydro-
■■ chlorination of 2-chldro-2,3,3-trimethylDutane
0*1 mole of 2-propanol, formed "by oxidation of the G-rignard
reagent, found in an azeotrope with 2,3j3-trimethyl-l-
2.2 moles of recovered 2-chloro-2,3,3-trimethyl'butane
3.1 moles of 2,3,3-trimethyl-2-"butanol, presumably "by hydrol-.
■ ysls of the chloride
1.05 moles of crude 2,2,3,3,4-pentamethylpentane
This represents a yield of k,0 percent. Another run, in which I9.V3 moles
of the -chloride was used and which was kept at. 5° C for 3 weeks, then, at
room temperature for 2 weeks, yielded 0.6 mole of additional crude (3.1-
percent yield) .
The combined yield of crude material (300 ml) was fractionated in
Column 8. From this distillation .there was obtained 226 ml of material
which "boiled 163.7 to l6U° C (uncorrected).. This product was redis-
tilled in the same' column, and there was collected 186 ml of constant-
boiling, constant-refractive- index material. The physical constants of
this product after filtration through silica gel were: freezing point
-37.5° C, np 2 ° ■ 1.^361, d 20 = 0.7803, tolling, point 165.5IJ. to I65.56 C
at 750.5 millimeters of mercury.
Later, two other methods for the' preparation of this decane were
investigated. Both of these methods involved the methylation of 2,2,3,U-
tetramethyl-3-chloropentane. This chloride was prepared in good yield
from the corresponding alcohol "by reaction with concentrated hydrochloric
acid. The chloride decomposed easily when a "boiling-point determination
was attempted at atmospheric pressure. It would not crystallize at dry-
ice temperature and had an index of refraction np 20 of IA389. The
30 NACA TN No. 12^7
carbinol was prepared "by the reaction "between n^thylmagne s^lum "bromide
and 2,2,^-trimethyl~3-P9ntanone. '..',■'■ '' ; , ......
i .• * * t ' ' ,"•? . ' ! ».''■...
In one experiment (November I9V3) on the me'thylatioh of ttiiB' chlo-
ride, 1.7 moles of the chloride in 320 ml of "benzene was. added to ,2.5
moles of dimethyl zinc, using the previously described 'teb^hnigue.. ' .Dis.-
tillation analysis pf. the- product of reaction shoved' the. presence of 0.,%
mole (23.5 percent).' .of 2-isbpropyl"-3,'3-dimethyl-i-hutene arid 0»8l mole . ■
(47.5 percent) .of 2',3,3,^tetramethyl-l-pehterie, "both' formed by. dehydror
chlorination of the alky 1. chloride . ' In Mditioh, ' there was found. .38.
mole (assuming C 10 H 22 ) of material which "boiled 150° to l6o° C, and from
which no pure material could "be isolated.
In another experiment (May 19kh) i 10.7 ; moles of '2,2,3, ^-tetramethyl-
3-chloropontane was treated with 11.0 moles of methylmagne slum ."bromide
in ether solution. ■ The reactiori waB allowed to 'take ..place . over, a period
of 3 weeks at 15° to 22° C. ■ The products of the reaction, as determined
"by distillation analysis, consisted of 3.0 moles (28 percent) of 2-iso-
propyl-3,3-dimethyl-l-"butene, and 5.7 moles .(53 percent), of 2,3,3,^-
tetramethyl-l-pentene, formed •"by/dehydrochlorination of the' alkyl chlo-
ride. In addition, there was found 0.5 mole (h.7 percent) of crude
2,2, 3, 3,^-pentamethylpentane (158°- to 16*7 P ' C, ■ n^ .* i',fc35^' to' 1 .U369) .
It is interesting to note that in "both of these trials., the dehydro-
chlorination of the alkyl' chloride 1 Ted' i;o approximately the same relative
proportions of the two nonenes) namely, one part of . 2r£sopropyl-3,3- .
dimethyl~l-"butene,' and;.' two. parts of : 2,3;3^'-tetramethyl-i-'pe'n : tene.. This,
proportion- is not the same &s occurs when the carbinol'. it self is deny'::
drated. in that case the. proportions are : three parts of 2-isopropyl-3,3-
dimethyl-l-"butene and one part of 2,3,3>^-tetramethyl-l-pehiene. ' (See
• Pentamethylpentanes from p^^A^-P'eniamethyi-S-pentanol -'■! ►-' In ,.
an attempt to prepare, 2,-2,3,4,^petttam£thyipehtane, .it has "been found ' ■ .
that ,2,2,3., ^., Vpe&teaiie'thyl-S-.p'enitariO'l will dehydrate . under the. .influence -
of iodine .to. a mixture of .two -decene'sj' which, on hydxogeriatioij, yields
"both of the. •pe'ntamethyl^pen'tanes; ;'■.■" ''"' : ' ■■"' ' •' ;■'* " .
$n 1933 Whitmore and Laughlin (reference 17) reported the dehydra-
tion of 2,2,3,^,U-pentamethyl-3-pentanol "by means of 3 -naphthalene sul-
fonic, acid to g£vev2rtrhutyl-3>-3*dimethyl-l-hut
rearrangement. They- also reported a' small amount of low-Trailing, ' uniden- :
tified. material.' -...-.. , ■ ; ■-..■.-: ■■■?' -•'■'
...... , i : -I- 1 .. ' ■" ' ■' .' ■ '
: ■ . ■ '.,".' ; '' -i ".' - : '■"' ' ■ ' ' ' . . r ., • ■", ■ '■ ■•
Since this reaction offered a means of preparing 2,2,3,U,^-rp'enta-
methylpentane t a trial ;"■ 3?un ; was made . • "When'' the' carbinol was' dehydrated
with p, ^naphthalene sulfonic ac id .>&t'-' atmospheric pressure, 5 the products
of the reaction consisted of isohutylene, 2,3-dimethyl-l-hutene,
NACA TN No. 12^7 31
2,3-dimethyl-2-"butene, and only a small ■ amount, of higher-hoiling material.
No 3j3-dlmethyl-l-"butene was found In the reaction products. Dehydration
of the car"binol with iodine was found to' yield- a mixture of decenes, com-
posed of 2-t-Tratyl-3,3-dimethyl-l-"butene and 2,3,3,li ; ,lt-pentamethyl-l-
(l ) Preparation of 2 T 2 T U-trimethyl-3"Peatanone and
Preparation of 2,2,*l--trimethyl-3-pentanone was made "by the Haller-
Bauer synthesis (reference 2k) in toluene solvent "by the action of sodium
amide and then methyl sulfate on 2,U-dimethyl-3-pentanone. Sodium amide
was made in 90- to ^-percent yield "by the method described in reference
25. The crude 2,2,it--trimathyl-3~pentanone was methylated a second time
"by the same method to give 2,2,k,4-tetranethyl-3-pentanone.. The manipu-
lative details of these reactions are described "by Whitmore and Laitghlin
in reference 17 . The over-all yield was 58 percent of that theoretically
possible, calculated without including recovered 2,lf--dimethyl~3 i -pentanone
and 2,2,4-trImethyl-3-'pentanoiie, which were recycled in the synthesis. A
charge of this ketone was fractionated in Column 1, for the isolation of
a pure sample for physical-constants measurements. In the same column,
a sample of the 2,2,^,l4--tetramethyl-3-pentanone was also, distilled for
the, Bame. purpose .
(2) Preparation of 2,2,3A t ^-psfttamet;h,yl-3-pentanol
A, solution of 10 moles of methyl magne si urn "bromide was reacted with
8.75 moles of 2,2,4,^-tetramethyl-3-pentancne and the product worked up
In the usual manner. Fractionation of the product in Column h at a pres-
sure of 5? millimeters of mercury gave a forerun of 307 ml of material
which "boiled "below 105° C . At this point the carMnol "began to solidify
in the condenser and the pale yellow material remaining in the pot was
found to "be quite pure carMnol (melting pcl::t ahove 37° C) . A portion
was recrystallized from ether for use in the determination of physical
properties . The yield amounted to 75 percent of the. theoretical quantity.
(3) Dehydration of 2,2,3,U»fr-P6ntamethyl-3-pentanol
with g -naphthalene sulfonic acid . .
Dehydration of 897 grams (5.7 moles) of 2,2,3,lj-,^-pentamethyl-3-
pentanol with 8 grams of 3 -naphthalene sulfonic acid under a fractionat-
ing column resulted in the distillation of a water layer, an organic
layer (855 ml), and ahout 50 ml of material collected in a dry- ice trap.
The organic layer, which smelled strongly of sulfur dioxide and hydrogen
sulfide, was washed, dried, and distilled from sodium, and gave the fol-
NACA TN No . 1247
54 to 57
51 to 71
71 to 73
73 to. 75
75 to 150
150 to 153.2
153.2 to 156.5
156.5 to 157
a Dietillation interrupted.
A considerable quantity of gas was evolved during the- distillation.
This gas "boiled at a"bout -4° C, was readily absorbed in sulfuric acid,
and absorbed bromine. Regeneration froc. sulfuric -acid solution by neu-
tralization resulted in t-butyl alcohol. This identifies tho g.?.s as iso-
butylene. 1'he other principal products of the reaction were .fraction
2(2,3-dimethyl-l-butene), fi action 5 (2,3-dimethyl~2-butene), and frac-
tions 7 and 8, which probably contained a mixture of 2,3,3,4,4-pente'-
methyl-1-peritene and 2-t-butyl-3,3-dimethyl-l-butene. Since the products
of this distillation did not yield the desired.' compounds in any appreci-
able quantity more elaborate analysis was not" undertaken .
(k) -Dehydration , of 2/2,3,4^4-pentemethyl-3-pentanol
with id&ine ! ,
■" A charge of 2.2,3,4,4-pentaime'thyl-3n>5r-+8Tiol (640 grems, 4.1 moles)
was refluxed with 4 grams of iodine and the product distilled through a
short' fractionating column, yielding 70 ml of water and 700 ml of organic
material. The organic layer was washed > dried, and fractionated roughly.
The distillates from three runs were combined, yielding I950 ml of mate-
rial which, on further fractionation, gave 1800 ml boiling 140° to 155° C.
The residue was semisolid and had an odor similar to that of a carbinol.
The 140° to 155° C fraction waa redistilled into the following fractions:
NACA TN No. 12^7
Refractive index, n D ao
100 to 1W.2
2A8.2 to 1^9.0
1^9*0 to lk-9,6
149.6" to 151.0
1A355 ;:■ ■
151.0 to 152.0
1.A367 - ■ ■
152 e0 to 153.0
153.0 to 155.0
1.^39$ -.-■ ■
155.0 to 157.0
A constant-hoiling portion of fraction 3 was reserved for determi-
nation of physical constants and ozonoiysis . At 157° G, solid .material
started to form in the condenser; so the distillation was stopped. The
cooled residue in the flask was solid, melting at 3^.5° to :37«5° C-, "but.
a mixture of this compound and the original carbinol was liquid at room
temperature. The material was soluble in ether, insoluble, in water,
slightly soluble in 85-percent phosphoric acid and was . unaffected "by
Analysis showed the presence of 83 .1 percent .carbon and 13.8 per-'
cent hydrogen. Because of the volatility of' the compound, these results
Stty bo low. By extending the CH content to total 100 percent, the anal-
ysis was calculated to 85.8 percent carbon and 111-. 2 percent hydrogen,
which agrees with the analysis' of an alkene. The molecular weight was
found cryoscopically to "be lU2.k (theory for
c ioSbo'- lk0 ' 1 ^
At this point the distillation of the solid olefin was continued
after -provision had "been -made to. prevent solidification of material, in
the .condenser.- This distillation gave the following fractions 1 • ■•
157.0 to 157.2 ■
157.2 to 158.0-
158.0 to 158.2
158.2 to 158.2
158.2 to 158.9
I58.9 to 159.0
159.0 to 159.0
Ozonolysis was performed on fraction 15.
3^ NACA TN No . 12^7
(5) Ozonolysie of Alkenes
(a) Lover-"boiling alkene (2-t-T3utyl-3,3-dimethyl-l- '
Ozonlzation of 0.21 mole of alkene in 300 ml isopentane at ~5° to
-10° C was accomplished in 12 heirs. Oxygen containing 7.5 percent ozone
was used at the rate of 7500 ml per hour. The solvent was not removed
prior to decomposition, "because the ozonide proved 'to "be a solid. Decom-
position was effected "by means of the technique developed "by Whitmore and
Church in reference 26 » The reaction was of medium violence and gave
rise to 36.5 ml of oil and 150 ml of water layer. Analysis of .the water
layer showed the presence of 0.18 mole of formaldehyde and no other low-
molecular-weight aldehyde or ketone. The oil was distilled to yield
2U.3 ml of 2,2,^,4-tetramethyl-3-pentanone ("b.p. 150° to 155° C), which,
when treated with methylmagae si urn "bromide, gave 2,2,3,U,^-pentamethyi-"3-
pentanol, the identity of which was proved "by a mixed melting point with
a known sample .
(Td) Eigher-"boiling alkene (2,3,3,^,l+-pentamothyl-l-
Tn the same manner as described, 0,11 mole of the higher-boiling
alkene was ozonized in 300 ml of isopentane at -10° to -20° C to yiold
0.071 mole of -formaldehyde and 9 grams of an oil. ("b.p. 172° C,
nj) 24 ss 1 .it-lM?) . This oil gave a positive iodoform test, and • was oxidized
"by 50 -percent nitric acid to 2,2,^,3-tetra^ethyl'butanoic acid. (See ref-
erences 27 and 28.) After sevoral crystallizations from alcohol, this
acid melted at- I96 to 197° 0, the same value repdrted in reference 29.
The neutral equivalent was found to "be 1^7-3 • The amide was prepared and
found to melt at 201.5° to 202<,2° C, which agrees with the melting point
(201° to 202° C) found in reference 29. The ketone gave a 2,l|-d:!nitro-
phsnylhySrasone which melted at 182° to 183° C . The ketone was therefore
considered to "be 3,3,^,4-tetrejaethyl-2-pentaiione. (Analysis: IT found^
17.20, 17.28 percent,* calculated for CisHgaBf/iOej 17-27 percent.)
■■ (6) Hydrogenatiori of thedeceries
The crude lower-"boiiing alkene from the dehydration of 2, 2, 3,1+, h-
pentaifl.ethyl-3-pentanol (fractions 2 to 8) was hydrogenated and filtered
through silica gel. Distillation in Column 5 gave:
NACA TN Ho. 1247
• (Head temper attire)
Refractive index, ;• n^
1 to 2
3 to 8
9 to 14
15 to 16
153.4 to 158.4
158.4 to 159.8
. 159.2 to 161.7
I.4296 to 1.4304
. 1.4306 to" 1.4307 .
1.4307 to 1.4313
1.4320 to '1.4341
An analysis of the distillation curve showed the presence of 735 ml of
2,2,3,4,4-pentamethylpentane and 112 ml of 2,2,3,3;4-pentamethylpentane..
Hydrogenation of the higher-foiling ■ alkene was carried out 'in- a' '
solvent (2,2,4-trimethylpentane) .. Distillation gave, in addition to the
solvent, a small forerun, and 247 ml effractions collected at 163 to . = '■_
164° C (np 20 » 1.4358 to I.4361). The test: samples of "both decanes were:
reserved for measurement of physical constants. " : " • '■ ;
The yield of alkanes isolated in the.' pure state (calculated on "■'
2,2,4,4-tetramethyl-3-pentanone) amounted to 25.8 percent: of 2,2,3,4,4-
pentamethylpentane and .11.4 percent of 2,2,3,3,4- : peritamethyiperitane. .
These yields could' not T>e used to form a definite" 'opinion of the reac- '
tion, nor can much weight "be placed .on the ratio of 'products found,
since a loss experienced in the distillation and handling of the higher
■boiling decene is not accounted fori _-■"■
Fentamethylpentanes from ."2, ; 2 t -3,4,4-pentamethyl-3-peri-6anol'- IX »- ■
The second run of this series of reactions was made' to increase -the ■'■■
stock of hydrocarbons and to obtain more' information -on the ratio of '
products formed "by dehydration 'of the carhinbl. ■ •'■ : "
: Cl) .Preparation ! 'of :2,g,4--trimethyl-3-pentaribne '
For this' second 'synthesis,- "an easier method was' devised for making
2,2,4-trimethyl-3-.pent'anone. ThiB "method ■■was "an" adaptation of that de- '
scrihed: "by Nef- in reference '30 vhb obtained ' this 'ketbn'e "by the -Exhaustive
methylation of acetone, methylisopropyl ketone, diethyl ketbrie, or
pinacolono with methyl iodide and potassium hydroxide in a sealed tube
at l40° C. The-method used in' the. present ..work" euhTstittit'ed.; the less ex-
pensive methyl "bromide for methyl iodide in the methylation of commercial
2-,4-dimethyl-3^pentanone. " ■ ? .'.•■'. ■•:.•'... "' . .-.■-■ '.■■"■■■ ' ' ' * '•■■'•'■'
• Several .runs of various ''sizes were 1 made 1 and" the results are 'sum-
marized in -the fdllowirig- ta"ble: >■■.-- 1 ;■'.;■ ■■; .- + ■ • '1-': .■■■;,'.
NACA TN No. 121+7
METHYLATION OF 2,U-DIMElTHYL-3- : PE3STAT5rOKE
Yield of 2,2,1+-
CH 3 I (1.5)
(CH 3 )^50 4 (1.5)
ll+Q. to 160
CH^Br (1+) '."
160 to 170
ll+O to 150
CH 3 Br (1+)
190 to 200
CE 3 Br (1+) '
190 to 200
200 to 215
CH 3 Br (U7.7)
19P, to 200'
CH 3 Br (1+7.7)
200 to 230
''Based on 2,l+-dimethyl-3-pentanone consumed.
These reactions were carried out in hydrogenatipn' "bombs. The "bomb
was chilled "by Bolid carton dioxide and charged with the. reactants, then'
sealed and heated to the temperature indicated. 'Since the reaction. is
exothermic, it was "found difficult to hold a predetermined narrow temper-
ature range. (The operation could probably "be made, more efficient "by
pumping the methyl- "bromide into the reaction vessel as it is consumed "by
the reaction in order.. to obtain more sta^e reaction conditions.) When
the reaction wds complete the bomb was copied and the contents washed
•well with watery dried, and fractionated. In 'one experiment an attempt
was made to distill the residue (2l+7 grams) . It was found to contain
lachrymatory-materials., "but little, if any,' 2,2,lfc,l+-t6tramethyr-3-
pentanone. None of this compound was found "by Nof in any. of his methyla-
* ' ■■..-..
(2) Preparation of g^.l+^-tetramethyl-S-pentanone
While tho preparation of 2,2,l+-trimethyl-3-P©ntsnone was in progress,
a now and simpler method for synthesizing 2,2,l+,l+-tetramethyl-3-pentanone
was described "by Bartlett and Schneider, (See reference 23.) This new
procedure eliminated entirely the necessity of using sodium amide in the
NACA TIT No . 12^7 37
synthesis • The Bartlett and Schneider reaction involved Interaction "be-
tween t-.butyl chloride, methyl, trimethylacetate A and sodium sand to give
a mixture of 2,2,^,lj;-tetramethyl-3-pentanQne/ and: 2,2, i f-,lv-tetramethyl-3
pentanol. as. major products. _ ■"
Several small-scale runs (1.6 to 2.0 moles) of this reaction were "
made. There was no appreciable difference in the yields of di tertiary-
"butyl, compounds from reactions In which •technical isooctane (2,2,l; : -
trimethylpentane) was used as a solvent and those in which isopentane
was used. Since the former solvent is considered safer, it was used in
the majority of the trial runs and In the large-scale run. Slightly
larger (2 to 5 percent}' yields were chtained "when sodium sand was used
rather than Bodium wire'. In none of the small-scale runs did the yield
of- combined di tertiary-butyl compounds 'exceed 53 percent. (Bartlett
and Schneider report yielde up to 71 percent.) ' After the technique for
handling this roaction had been sufficiently developed, a large run was
made in the stainless-steel kettle.'
(a) Methyl trimethylacetate
To a solution of 53 kilograms (177 moles) of sodium dichromate di-
hydrate (technical) in 98 liters of water in the glass-lined reactor was
added 39.9 litors of concentrated sulfuric acid. The' solution was heated
to 82° C and 6.6 kilograms (59 moles) of 2,^,4-trimethyl-2-pcntene (97
percent pure) was added over a period of 5 hours. The rate of addition
was regulated so that the temperature of . the' mixture did not exceed 88° C.
Thon about 3 liters of methyl alcohol was added to use the excess dichro-
mate, .and the mixture was subjected to steam distillation. There" were -
obtained 5*76 kilograms of organic layer and about 36 liters of aqueous
layer. The aqueous layer yielded, on distillation, an additional 0.82
kilogram of organic material. The crude product was distilled In ColV •
uinns k and 5, and yielded 3.91 kilograms of trimethyl acetic acid' (b.p.
l6o° to I65 C) 65.O percent yield). The methyl ester of trimethylacetic
acid was prepared In the usual manner by' refluxlng a solution of the'
acid in methyl alcohol. Sulfuric acid was used as the catalyst.
(b) 2,2,|t,J<-Tetramothyr-3-pentanone '
Sodium sand, from 6.8 kilograms (300 moles) of sodium was prepared
under toluene (22 liters) in the usual manner. The mixture was cooled
to 15° C and 16 liters of technical Isooctane (2,2,l*-trimethylpentane)
and 16 kilograms (173 moles) of t-butyl' chloride were added. ■ After the
reaction was Initiated by the addition of a small quantity of ester, the
remainder (total 7«98 kg, 68.5 -moles) was added during % hours, whilo
'the temperature was maintained at 35 to- 1*0° C . Stirring was continued
for 8 hours, then the mixture was allowed to stand overnight . The- prod-
' uct was worked up in the manner described by Bartlett and- Schneider in
reference 23. Distillation -gave 2.57 kilograms (18.1 moles) of-'2y2,l*-,^.-
•38 NAG A TN No. 12^7
tetramethyl-3-pentanone (b.p. 151.5° to I56.O C), 666 grams of Inter-
mediate, .and 2 .72 'kilograms (18,9 moles) of 2,2,4,k-tetrametbyl-3-pentanol
("b,p. 167° to 173° C).. Including the intermediate, this represents a
yield of approximately 6l percent, "based on methyl trimethylacetate .
. The carMnol fraction and the intermediate containing carbinol were
combined and oxidized in two batches. In each batch I.36 kilograms'
(9A5 moles) of carbinol and 333 grams of intermediate were suspended in
a solution of 1255 grams of sodium dichromate dihydrate in 1170 ml of
water. ■ While the reaction mixture was held at h5° to 60° C, a solution
of 2300 ml concentrated sulfuric acid in 2170 ml o'f water was added dur-
ing 2 days, after which the reaction mixture was stirred and heated to
50° C for 1 day. The organic material was then steam distilled, dried,
and fractionated. There was obtained 1.35 kilograms (9*52 moles) of
ketone (b.p. 151° to 15^° C; 78 percent yield).
In the same manner, all the 2,2,l}-,U-tetramethyl-3-pentanol obtained
in the several preliminary runs was oxidized to ketone, and all the
ketone from the several sources, was combined. This included a small
amount prepared by the Haller-Bauer reaction. (See reference 2k.)
(c) Preparation and dehydration of 2,2, 3, 4, it-
pent amethy 1-3 -pent anol
The 'pentamethylpentanol was prepared in the manner already described.
Prom 6i$6 kilograms (U9.C moles) of 2,2.Uj^-tetramethyl-3-pentanone there
was obtained k.8k kilograms (30.6 moles) of 2,2,3, k,k- pentamethyl~3-pentanol
(62.6 percent yield). Dehydration of the carbinol was caused by refluxing
with iodine.' In a trial run, 332 grams (I.98 moles) of carbinol was
boiled with 3.3 grams cf' iodine. During 2 hours, 93 percent of the theo-
retical quantity o:C water was eliminated and collected. The organic layer
was washed with sodium, thiosuifate solution and with water, dried, and
distilled in OoIigki 17 . The charge was 2^6 grams. The decene fractions
(b.p. 1^5° to 158,9° C) weighed 216.6 grams (1.5^ molesj 78 percent) .
Analysis of the distillation' curve shewed that these fractions consisted
of equal parts of the two isomers, 3,3,-dimethyl-2-t-butyl-l-butene and
2,3,3, i 4-,U-pentamethyl-l-pentene. Treatment of the main portion cf the
carbinol for the preparation of the pentamethylpentanes followed the pro-
cedure already described. ■ : '
2,2,5,5-Tetramethylhexane and 2,2,U,5-Tetramethylhexane
The synthesis of 2,2,5,5- and 2,2,lf-,5-tetramethylhexanes was accom- ' .
plished by the following reactions: (a) oxidation of 2,l*,^-trimethyl-l- ,.
pentene to ^,lf--dimethyl-2-pentanone (methyl neopentyl ketone), (b) oxida-
tion of this ketone to t-butylacetic acid, (c) conversion, of the acid to
methyl. t-butylacetate, :(d) -reaction of the ester with "Vbufylinrigneslum ..
MCA TN No. 12^7 39
ohlorlde to give 2,2,5,5-tetramethyl-3-boxanol, (e) dehydration of the
carbinol to a mixture of 2,2,5,5-tetramethyl-3-hexone, 2,3,5,5-tetra-
methyl-2-hexene, and 2,3,5,5-tetramethyl-l-hexene, and (f) hydrogenation
of the first-named alkene to 2,2,5,5-tetramethylhexane and of the last
two alkenes to 2,2,11-,5-tetramethylhexane.,
Oxidation of 2A.^-trimethyl-l--pentene ,- The' oxidation of 2,k,k-
trimethyl-1-pentene was carried out essentially in the manner disclosed
by Whitmore, Hameyer, and Trent- in reference 15 . Several runs were made
using olefin of 95-percent or higher purity. (The isolation of this
olefin is described later.) In a typical run, 101 moles of alkene was
oxidized during 10 days with sodium dichromate "by the slow addition of
sulfuric acid. There were obtained 1800 grams of acidic material and
.9360 ml of neutral oil which, upon distillation in Column 3', gave 215lj-
ml of forerun, if-150 grams (3&A moles) ^lt-dimethyl-2-pentanone (b.pv
123° to 126° C), and 2000 ml of residue. This yield of ketone is equiv-
alent to 36 percent of the theoretical amount. The aoidic material was
found to "be a complex mixture containing only minor quantities of tri-
methylacetic and t-butylacetic acid,, and was not further investigated.
Oxidation of . methylneopentyl ketone .- The hypohalite oxidation of
the methylneopentyl ketone to t-butylacetic aoid was accomplished -"by a
modification of the reaction disclosed in reference 15. There sodium-"
hypobromite (prepared from bromine and sodium hydroxide) was used,, while
in the present work ! the- less expensive, commercially available calcium ■
hypochlorite was used. Several small preliminary runs were made to "
develop familiarity with th& reaction "before a large run was undertaken.
Three- large runs- were made, ono of which is_ described.
-■ A' solution- of 1^.0 kilograms of technical sodium' hydroxide in 38
liters' of water was prepared. This .solution was cooled to 19° C.and to
it were added .about 90 kilograms of cracked ice and 13 kilograms of. com-
mercial calcium hypochlorite (70 -percent chlorine). The temperature
thereby obtained was about -k° C. The ketone (50 moles) was then added
during 3' hours. The temperature of the reaction mixture remained below
+5° C during this addition. An additional 25 kilograms of cracked ice
was added and the mixture stirred for 10 hours, after which it was
heated to '6*5° to 70° C for 5 hours. After cooling the mixture to 20° C,
I9.7 liters 'of sulfuric acid was added slowly and the products steam '
distilled. The crude product' was distilled in several batches from a
1-liter Claison flask.- There was obtained U070' grams (31 .3 moles; 63 -'
percent) of acid collected between 180° and I9O C. No further purifi-
cation of the acid was made. >
Conversion of t-butylaoetic acid. to methyl t-butylaoetate .- The.
methyl ester of t-butylacetic .%ac id was made in the orthodox manner.- In
a typical run .a solution of ItlUO grams (35*7 moles)- of. acid and 300 ml
of concentrated sulfuric acid in 10 liters (250 moles), of methanol was
kO NACA TN No. 121+7
heated to reflux for two periods of 7 hours each. The crude product ob-
tained was' distilled in Column 5 and gave 3560 grams (27 ,k moles ; 76.7
percent) of ester, which was collected at 125° to 127° C.
Preparation of 2 » 5 , p , 5-tetramethyl-3-hexanol . - The preparation of
2,2,5,5~tetramethyl-3-hoxanol was carried out by the use of the reaction
described by Moersch (reference 31) which is an adaptation of that used
by Heyd (referenoe 32}.
To the ■ G-rignard reagent prepared from 326 gram atoms of magnesium
and 32'S moles of t-butyl chloride, there was added 6815 grams (52 .k
moles) of methyl t-butylacetate during 8 hours. The reaction mixture
was refluxed 7 hours each day for 3 days and allowed to stand each night.
Decomposition was caused by dilate- sulfuric acid (17 kg concentrated
acid and 20 kg water and ice). The' product was steam distilled, and the
aqueous layer extracted with ether. The organic layers were combined
and the ether removed in Column- 11. The residue was redistilled in Col-
umns 2*4- and 7, yielding 6507 grams of carbinol collected at 166° to
170° C- This' is equivalent to Ul .2' moles or 79 percont yield. Moersch
reported 85 percent yield (reference 31) •
Dehydration of 2 , 2 , 5 , 5 - tetramethyl- 3-hexanol . - Three preliminary
experiments were made on the dehydration of this carbinol and on the re-
arrangement of the resulting olefins. In one run> 117 grams (0.70 mole)
of carbinol was passed over 256 grams (330 ml) of alumina (Baker Hydralo,
lot 919^2) at 300° to' 305° C at the rate of kj grams per hour. The cat-
alyst tube was '2.5 centimeters in diameter. The water recovered amounted
to 10.8 ml (0.6 mole; 86 percent). The product was dried and fraction-
ated in Column 17. The yield of decenes amounted to 70 percent (78 per-
cent on basis of carbinol consumed), and consisted of 3^.5 mole percont
2,2,5,5-tetramethyl-3-hexene, 35*2 percent 2,3,5,5-tetramethyl-l-hexene,
and 30.2 percent 2,3,5,5-tetramethyl-2-hexene.
In another experiment, 118 grams of carbinol was dehydrated under
the same conditions, except" that the rate was 98 grams per hour. In
this ca3e, a yield of k6 percent olefins "(73 percent on basis of carbinol
consumed) was obtained. The mixture of olefins contained 3^.8 percent
2,2,5,5-tetramethyl-3-hoxene, 1*2.0 percent •2,3,5,5-tetramethyl-l-hexene,
and 23.2 percent 2,3,5,5-tetramethyl-2-hexene.
To determine the extent of rearrangement of the 'olefins, a mixture
of decenes was passed over the catalyst at 300° to 310° C at the rate of
kk grams per hour. Analysis of the resultant mixture showed that the
original mixture was isomerized as follows: 2,2,5,5-tetramethyl-3~hexene;
from 13.5 percent to 16.8 percent; 2,3,5,5-tetramethyl-l-hexene; from
h6.2 percent to 31.2 percent; 2, 3, 5 ^- tetramethyl- 2- hexene, from Ij-0.0
percent to 52.0 percent. ■ \ ■
NACA TO No. 12l;7 'H
The bulk of the carbinol vas dehydrated in the manner used in the
first experiment. The resultant mixture vas dried and distilled in Col-
umn 5. The carbinol recovered vas recycled for dehydration. In this
vay, U999 grams of crude olefin mixture vas obtained (86.6 percent yield).
This mixture vas separated roughly in Column 5 into concentrates "boiling
121° to 127° C, 139° to IU5 C, and 152° to 158° C, and intermediate
fractions. A sample (500 ml) of each hydrocarbon vas redistilled in Col-
umn 17 for preparation of pure compounds. The impure fractions from each
of these distillations vere returned to the appropriate concentrate.
These olefins have "been identified previously. (See references 31 and 32.)'
Hydrogenation .- Each of the olefin concentrates vas hydrogenated
separately, as vas the combined intermediate. The last tvo olefin con-
centrates gave the same paraffin and vere combined for distillation.
Purification of both paraffins vas accomplished in Column 18. The best
500 ml samples from each distillation vere redistilled in Column 17, and
physical constants vere measured on the best samples from these distilla-
2, 2, 3, 3-Tetramethylhexane '
This hydrocarbon, vhich vas synthesized at Pennsylvania State College,
vas purified in these laboratories. When received, the sample (2 gal)
contained chlorides vhich vere removed by boiling vith alcoholic alkali.
The product vas vashed, dried, and ' fractionated in Columns 19 and 20. The
best portion from one of- these distillations vas refractioriated in Column
17. Physical constants vere ■ determined on the best fractions from this
*3,3,^, 1 <--Tetramethylhexane ■■'
The method of preparation of this decane is similar to that used in
the preparation of 2,2,3,3-tetramethylpentane, and involved the reaction
between ethylmagnesium chloride and 2,3,3-trimethyl-2-chloropentane.
In the exploratory synthesis. 2,3,3-trimethyl-l-pentene (b.p. 108.3l<-
to 108. k0° C, n D 2 ° «s l.lt-170 to I.U172) vas converted to the chloride,
2,3,3-trimethyl-2-chloropentane, by reaction vith dry hydrogen chloride
at -30° C. The product vas fractionated in Column k. The forerun of un-
changed olefin vas used in the preparation of more chloride. The chloride
used in the coupling reaction vas that oollected betveen 8l° and 82° C at
57 millimeters of mercury.
To the Grignard solution prepared from 10 gram atoms of magnesium
and 10 moles of ethyl bromide, there vas. added,- during 7 days, 9.3 moles
(1382 grams) of the chloride. On the twelfth day the mixture was vorked
up. The ether vas removed from the organic layer and the residue refluxed
6 hours vith alcoholic alkali (10 percent KDH) to remove chlorides. ■ The
42 NACA TN No. 12^7
washed, dried, chloride-free material was distilled in Column 17 . A
large run of the preparation of this hydrocarbon is in progress, From
this run a considerably purer compound is expected.
2,3-Dimethyl-l-Butene and 2,3-Dimethyl-2-Butene
The preparation and properties of 2,3-dimethyl-2-butene and 2,3-
dimethyl-.l-butene have "been reported previously in reference 5. While
the 2,3-dimethyl-l-butene reported was relatively pure, the 2,3-dimethyl-
2-butene was decidedly impure. The "boiling range of the best sample of
the latter was about 0.k° C, even after repeated fractionation} whereas
other hydrocarbons prepared and reported in the same paper had boiling
ranges of less than 0.01° C. The wide boiling range has been attributed
to the presence of peroxides in the sample. This tendency to form perox-
ides is much more pronounced in the 2,3-dimethyl-2-butene than in the
one isomer. Since both alkenes result from the same reaction, the study
of both compounds was repeated. The method of preparing the alkenes was
dehydration of 2,3-dimethyl-2-butanol by means of iodine. The carbinol
was prepared by action of methyl magnesium bromide on methyl isobutyrate.
Several batches of methyl isobutyrate were made, in each of which
90 moles of methanol and 30 moles of isobutyric acid were refluxed for
6 to 8 hours with 15 ml of concentrated sulfuric acid. The product was
recovered by adding water, extracting the unchanged acid by sodium car-
bonate solution, and saturating the aqueous layer with salt to recover
unused alcohol and dissolved ester. The combined, nonacidic organic
layer was distilled in Columns 3, h, 5, and 6. Only constant-boiling
(±0.1° C) material, was reserved for subsequent steps. The yield amounted
to 71 percent of the theoretical based on original isobutyric acid.
In a typical run of the preparation of 2, 3-dimethyl-2-butanol k2
moles of methyl isobutyrate was added to 90 moles of methylmagnesium bro-
mide in 12 hours. After the reaction mixture had been allowed to stand
for 15 hours, it was warmed for h hours and then treated with ice and
dilute hydrochloric acid. The organic material was dried and distilled
in Column 6. After ether and unchanged ester had been removed, tho car-
binol was distilled at j6.k° to 76.6° C at 152 millimeters of mercury.
The yield *ras 3120 grams (73 percent, based on ester) .
The dehydration of 2,3-dimethyl-2-butanol was accomplished by heat-
ing it with 1 gram of iodine per liter of carbinol. The olefinic mate-
rial thereby obtained was roughly separated in Column h and consisted of
approximately three parts of 2,3-dimethyl-2-butene and one part of 2,3-
dimethyl-2-butone . The residue from' this distillation consisted of un-
changed carbinol which had steam distilled during the dehydration step.
This carbinol was returned to the dehydration process as it accvmulated .
In this way, a practically quantitative yield of alkeneB was obtained.
KACA TU No . 12V7 I4-3
Two charges of crude 2, 3-dimethyl-2-butene were fractionated in Col-
umn 1. The middle cuts from these distillations, the fractions of which
had a constant refractive index (±0.00005), were combined, and amounted
to 3.6 liters of material. The 2, 3~dimethyl-l-butene was fractionated in
like manner, and 3.5 liters of material was obtained. The two hydrocar-
bons were then subjected to distillation in Column 5 under conditions de-
signed to destroy any peroxides present and to prevent their formation in
the distillate. This was accomplished by adding hydro^uinone to the dis-
tillation charge and by keeping the column, take-off, and delivery systems
flushed with nitrogen. In this way, thirty-three 100-ml fractions of each
hydrocarbon were obtained.
For measuring the physical properties of these olefins the same appa-
ratus and methods previously described were used, but care was exercised
to displace air in the apparatus with nitrogen during the determinations.
Refractive indices were measured in the usual manner. Peroxide numbers
(moles of active oxygen in 1000 liters of solution) were determined by
the method of Yule and Wilson (reference 33) .
For 2,3-dimethyl-l-butene, fraction 17 was used for determination of
refractive index and density. Tho peroxide number of this fraction was
0.03. Measurements of boiling points of this olefin were made with frac-
tions 16 and 19. The distillate from these determinations contained an
unmeasurably small amount of peroxide. The freezing point of ii.3-
dimethyl-2-butene was made on fraction 17 (0 .07 peroxide number) .
Refractive-index and density measurements were made on fraction 21 (0.03
peroxide number), and boiling-point measurements on fractions 18, 19, and
20 (O.Olj- to 0.06" peroxide number). The measured values of the properties
are given in table 2.
Considerable difference of opinion exists regarding the freezing
point of 2.3-dimethyl-l-butene. Schurman and Boord (reference 3k) report
a "melting . point of -120° to -123° C on material having a boiling range
of 0.U° C. Brooks, Howard, and Crafton (reference 5) report a freezing
point of -1^0 .1° C on. a sample of high purity which, however, undoubtedly
contained some peroxide. Kistiakowsky and. coworkers (reference 35),
using a sample having a boiling range of .01° C for use in determining
the heat of hydrogenation, ' reported that the material congealed to a glass
at low temperatures. Two attompts were made in this work to freeze sam-
ples which were peroxide-free, but. both were unsuccessful. An attempt to
freeze samples recovered from the boiling-point distillates, which had
been exposed to air for 2 weeks also failed. Attempts were made to freeze
samples containing small amounts of 2,2,l+-trimethylpentane,- those samples
containing O.58 and 2\k mole percent of this impurity -failed to freeze.
One sample containing I.U3 mole percent 2,2,^-trimethylpentane gave an
indefinite freezing point at -llj-5.lt- C. This value seems to substantiate
the previous value of -mo.l C (reference 5) and would indicate a very
low heat of fusion, which may be a controlling factor in the determination
of the freezing point.
kk NACA TN No. 12V7
The presence of peroxides caused a marked change in the boiling
ranges of these olefins. When samples of pure 2,3-dimethyl-l-butene
were distilled in the 'boiling-point apparatus, the observed temperature
changes (from 20 to 80 percent distilled) were less than 0.00V 3 C. The
same material, after exposure to air for 2 months showed a distillation
range (20 to 80 percent) of 0,11° C. Still more pronounced is the effect
of peroxides on 2, 3 -dime thy 1-2 -"but ene. Samples containing a smell quan-
tity of peroxide (peroxide number 0.0*0 distilled over a rango of
0.007° C or less, "but after this material had accumulated peroxides for
10 days the distillation range was found to "be 1.03° C.
In order to determine the .rate of peroxide formation under normal
laboratory conditions, samples of purified alkenes were allowed to stand
at room temperature in contact with air. Periodically, portions were
withdrawn ■ and analyzed for peroxides. The results of these analyses are
given in figures 3 and k. The great difference in rates of peroxide for-
mation in the two compounds may "be seen in. the comparison given in fig-
3-Methyl-2-Pentene (cis and trans)
The two geometric isomers of 3-methyl-2-pentene were prepared by
dehydration of 3-methyl-3-pentanol, which was formed by action of ethyl -
magnesium' chloride on 2-butanone .
To 53.8 moles of ethylmagnesium chloride was added 55.8 moles of 2-
butanone in 5 liters of ether. The yield of carbinol (b.p. 75° to 80° C
at ll)-2 mm Hg) was ko percent of the theoretical. The carbinol was dehy-
drated with p -naphthalene sulfonic .acid to yield a mixture of olefins. A
charge of 22*40 ml of the washed, dried olefin mixture was fractionated in
Column 2, which gave 2U0 ml of the .lower-boiling (cis ?) and 96O ml of the
higher -boiling (trans?) Isomers. Physical constants were measured on the
best samples of each isomer. Analysis of the distillation curve showed
that the original mixture contained 9.6 percent (by volume) of tho lowor-
boiling and T^+ percent of the higher-boiling forms.
The identification of these two olefins as cis and trans 3-methyl-
2-pentene, rather than the isomers 3-methyl-2-pentene and 2-ethyl-l-
butene, is based primarily on mass spectrometer studies. The two pat-
terns formed by analysis of the compounds obtained ar^ very nearly iden-
tical. No third component was isolated from the distillation, although
it is probable that one was present in small quantity.
Investigation of Diisobutylene
It was neoessary to isolate large quantities' of the two diisobutyl-
enos, 2,U,l|-trimethyl-l-penteno and 2,l)-,ij--trimethyl-2-pentene, in order
to provide samples for engine ■ studies and for the syntheses of k,h-
NACA TN No. 12^7 ^5
dimethyl-2-pentanone and trimethylacetic acid - "by oxidation. For this
purpose, a considerable quantity (kJO liters) of the commercial mixture
was systematically fractionated*
The original material was separated into five "cuts" or concentrates
by fractionation in Column 11. Because of the limited pot capacity, it
was necessary to perform this operation in "batches. Corresponding cuts
from each batch were combined. The data on these distillations are sum-
marized in table k»
Cut A (forerun) comprised an azeotrope containing a small quantity
of 2,i-Jj--trimethyl-l-pentene with butyl alcohol, along with other polar
compounds. This cut was not extensively investigated.
Cut C (58 liters), the intermediate between cuts B and D, was re-
fractionated in Column 11 to yield 3h liters of 2,k,i(-trimethyl-l-pentene
which was combined with cut B, Ik liters of intermediate which was not
further investigated, and 9 liters of residue which was added to cut D.
The augmented cuts B and D were then designated as Brl, and D-l, respec-
Cut B-l (298 liters) was found to be about 96.7 percent pure Q,k,k-
trimethyl-1-pentene,- its freezing point was -96. 5° Co A 170-liter por-
tion from the middle of this cut was refractionated in three runs and 72
liters of purified 2,i,l»-trimethyl-l-pentene was obtained, comprising
fractions with freezing points in the range -93 .59° to -93^55° C.
Physical constants were measured on one of the fractions of -93-55° C
material. These constants agree with those reported by Tongberg,
Pickens, Fenske, and Whitmore (reference 36) . This compound has been
identified by ozonolysis by Whitmore and Church (reference 26) .
Cut D-l (95 liters), a concentrate of 2,^,l(-trimethyl-2-pentene,
was refractionated in two runs. From these distillations, there was ob-
tained U9.3 liters of high purity 2,lt-,lj--trimethyl-2-pentene, composed of
fractions with freezing points from -106.62° to -IO6.58 C. A portion
was refractionated in- Column 1 for isolation of a sample for physical-
constants measurements. This compound was also characterized by Tongberg
and others (reference 36), and identified by Whitmore and Church (refer-
ence 26) .
The residue from distillation of cut D-l was 'fractionated in Col- ■
umn 1. From this distillation there were obtained two concentrates,
designated as D-2 and D-3.
Cut D-2 (7^5 ml, b.p. 106.8° C, n D eo = Lklkg to 1.U152,
d = O.7265) was probably an impure sample of 2,3,U-trimethyl-l-pentene.
Kuykendall (reference 37) obtained the. following properties for this
compound: b.p. 106.7° to 107.7° C, n^ 20 = i.klk6, d 2 ° = O.726.
h6 NACA TW No. 12^7
Cut D-3 (Sok ml, "b.p. 108.0° c, n^ 20 = l.kl62 to 1.1*171, d 2 ° » 0.733)
was a complex mixture in -which 2,3,3-trimethyl-l-pentene was the pro'ba"ble
major componorvt. This partial identification ie made "by a comparison, of
the physical properties of cut D-3 with those of the 2,3,3-trimethyl-l-
pentene isolated from Shell Hot- Acid Polymer, (See next section.) Since
only small quantities of these cuts (D-2 and D-3) were available, no ex-
tensive investigation was made on them.
Cut E was combined with tho residue from the preliminary fractiona-
tions. The combined material (27 liters) was fractionated in Column 11,
and yielded 3.8 liters of 3,>4-,li-trimothyl~2-p9ntene (cis and trans) ("b.p.
112.0° to 112.6° C, n D 20 = 1.^235, d so > 0.739) and if .5 liters of 2,3,4-
trimethyl-2-pentene Cb.p. 11.6.1° to 116.2° C, n D 20 = 1.4275, d 2 ° = 0.7428),
These two compounds were identified "by comparison of their physical prop-
erties with those of pure 3,4,4-trimethyl-2-penten© and 2,3,4-trimothyl-
2-pentene. The pure compounds were obtained "by the distillation analysis
of Shell Hot- Acid Polymer and "by dimethyl- zinc synthesis. Part of this
sample of 3,4,4-trimethyl-2-pentene was oxidized to pinacolone. The en-
tire sample of 2,3,4-trimethyl-2-pentene was hydrogenated to 2,3, 4-
trimethylpentane ("b.p. 113.41° 0, n D 20 - 1.4038 to 1.4o4o). •
An approximate analysis of the original diiso"butylene (gas-free
"basis) was made "by examination of the distillation curve's. This mixture
was found to contain:
2,4,4-trimethyl-l-pentene 70.0 percent ("by volume)
2, 3, 4-trimethyl-l-pentene|_
Polar compounds 2.0
investigation of Hot-Acid Polymer (Shall Oil Company)
The investigation of Hot-Acid Polymer was undertaken to isolate and
purify some of the major constituents. The general method of operation
was the same as that used in the investigation of diisohutylenes, "but for
this work more efficient, higher-capacity stills (12, 13, 14, and 16)
A total of .1041 liters of crude polymer -was subjected to preliminary
fractionation in five "batches. Corresponding cuts from the several
NACA TIT. Hb . 12^7 ^7
"batches were combined. In this way, the polymer was divided into five
portions. The data on these fractionations are given in ta"ble 5.
Cut A, which contained "butanol-2 was not further investigated. Like-
wise, the residue has not "been studied.
By refractionation of cut B, there were isolated the following mate-
Cut B-l - 1C3 liters, 2,U,l(-trimethyl-l-pentene, "b.p. 101.1° to
101.3° c/755 mm Hg, n D 20 > l.toSt to 1.4086*
Cut B-2 - 9,5 liters, a mixture of close-"boiling olefins, To .p.
107.0° to 107.1° c/756 ma Hg, n D 20 = l.hlAk to 1.4146
Cut B-3 - 8.0 liters, 2,3,3-trimethyl-l-pentene, "b.p. 108.0° to
108.1° C/753. mm Hg, n D 2 ° = 1.4173 to 1.4175
A considerable amount of material "between B-l and B-2 has not yet
"been investigated. This intermediate contains 2,4,4~trimethyl-2-pentene,
associated with at least two other compounds with "boiling points near
Cut B-2 was ref ractionated . The presence of several compounds is
indicated "by the distillation data. A sample of B-2 was hydrogenated .
Analysis of the product showed the presence of ahout 30 percent 2,2,3-
and TQ percent 2,3,4-trimethylpentanes.
Cut B-3 was refract ionated for isolation of a sample suitable for
physical-constants measurements. A sample of this material was oxidized
to methyl t-amyl ketone ("b.p. 130.8° to 131.2° C, n D 20 ■ 1.4201), of
which the 2,4-dtoitrephenylhydrozone melted at 111° to 112° C. Hydroge-
nation of a sample yielded 2,3,3-trimethylpentane ("b.p. 114.5° C,
np 20 = 1.U073).
Purification "by refractionation of cut C gave 100 liters of purified
3,4,4-trimethyl-2-pentene ("b.p. 111.7° to 111.9°C/751 mm Egj n D eo -. 1.4231
to 1.4233). The "best sample from this fraction was used to determine
the physical constants. The presence of cis and trans isomers, which
were only partially separated "by the fractionation, causes the wide- "boil-
ing range. It is thought that the sample reserved for physical-constants
measurements contained more of the higher-"boiling (trans?) isomer than of
the lower-"boiling compound. (Oxidation of this compound "by sodium dichro-
mate produced pinacolone in 30 percent yield.) '"
48 WACA TW Wo. 1247
Redistillation of 120 liters of cut D gave 45 liters of 2,3,4-
trimethyl-2~pentene (b.p. 116.0° c/754 mm Hg, n D 20 = 1.4271 to 1.4272),
National Bureau of Standards,
Washington, D. C, July 15, 1Q46
1. Brooks, Donald B., Cleaton, Eobette. B., end Carter, Frank E.:
Paraffin Hydrocarbons Isolated from Crude Synthetic Isooctane
(2,2,4-Trimethylpontane) . Ees. Paper 1027, Wat.Bur. of Standards
Jour.. Pes., vol. 19, Sept. 1937, PP. 319-337 •
2. Howard, Frank L.: Preparation snd Some Physical Properties of 2,2,4,4-
Tetram&thylpentane r Wat. Buri of Standards Jour, Pes., 'vol. 24,
June 1940, pp. 677-684.
3 . Brooks, Donald B . : Properties of Purified Normal Heptane and Isooctane
(2,2,4-Trimethylpentane) . Pes. Paper ll6o, Wat. Bur. of Standards
Jour. Eos., vol. 21, Dec. 1938/ pp. 847-852.
4. Brooks, Donald B., Howard, Frank L., and Crafton, Hugh C, Jr.:
Physical Properties of Purified 2,2,3-Trimethylp6ntane. Res. Paper
1259, Wat. B\jt. of Standards Jour. Ees., vol. 23, Dec. 1940, pp. 637-
5. Brooks, Donald B., Howard, Frank L., and Crafton, Hugh C, Jr.:
Physical Properties of Some Purified Aliphatic Hydrocarbons . Ees.
Paper 1271,.Wat. Bur. of Standards Jour. Ees., vol. 24, Jan. 1940,
6. Adkins, Homer: Reactions of Hydrogen, l&iiv. of Wis. Press, 1940,
ch. 3, PP. 29-43.
7. Brunn, Johannes H.: Laboratory Bub"ble-Cap Columns of Glass. Ind. Eng.
Chem., Anal, ed.,' vol. 8, May I936, pp. 224-226.
8. Whitmore, Frank C, and Lux, Albert E.: . The Absence of Rearrangement
of the Isobutyl Group during the Formation of Isobutylmagnesium
Bromide and Its Eolation to the Theory of Rearrangements. Jour.
Am. Chem. Soc, vol. 54, no. 8, Aug. 1932, pp. 3448-3454.
9. Mair, B. J.: The Synthesis, Purification and Certain Physical Con-
stants of the Wormal Hydrocarbons from Pentane to Dodecane, of n-
Amyl Bromide, and of n-Wonyl Bromide. Wat. Bur. of Standards
Jour. Ees., vol. 9, Oct. 1932, pp. 457-472.
NACA TN No . 12U? ^9
10. Whitmore, Frank C, and Badortscher, D. E.: The Yields of Some Ali-
phatic Tertiary Grignard Reagents. and the Limits of Their Usefulness
as Synthetic Reagents. Jour. Am. Chem. Soc, vol. 55 , no. h t April
193't, PP. 1559-1567.
11. Whitmore, Frank C, and Fleming, George H.: Preparation of Tetra-
methylmethane (Neopentane) and Determination of Its Physical Con-
stants. Jour. Am. Chem. Soc, vol. 55, no. 9, Sept. 1933, pp. 3803-
12. Hartman, W. W.: Methyl Iodide from Methyl Sulfate. Collective vol.
H of Organic Syntheses, A. H. Blatt, ed.-, John Wiley & Sons, Inc.
(New York, N. Y.) I9U3, pp. tO^-iK)5.
13. Aston, John G», and Messerly, George E.r Heat Capacities and Entro-
pies of Organic Compounds. II - Thermal and Vapor Pressure Data for
Tetramethylomethane from 13.22° K to the Boiling Point. The Entropy
from Its Roman Spectrum. Jovjc. Am. Chem. Soc, vol. 58, no. 12,
Dec. I936, pp. 235U-236I.
Ik. Cline, Edward Terry: The Synthesis of Type IH and Type V Olefins
f rom Dimethylhutadienemonohydrohromide . . . Ohio State Univ., Ph.D.
15. Whitmore, Frank C, Homeyer, A, H., and Trent, W. R.: Tertiary Butyl
Acetic Acid, U. S. Patent No. 2,00k,o66, June h, 1935 .
16. Whitmore, Frank C, and Cook, Newell C: The Decomposition of
Ozonides with Raney Nickel. Jour. Am. Chem. Soc, vol. 63, no. 12,
Dec I9U1, p. 35^0.
17. Whitmore, Frank C, and La\ighlin, Kenneth C: The Dehydration of
Tertiary Alcohols Containing a Neopentyl System. H - Methyliso-
propyl-tert-hutylcarhinol, Methyldi-tert-hutylcarbinol, and Methyl-
ethylneopentylcarMnol . Jour. Am. Chem. Soc, vol. 55, no. 9,
Sept. 1933, PP. 3732-3738. ■
18. Faworsky, Al.: Uber die Einwirkung von Phosphorhalogenverbindungen
auf ketme, Bromketme und ketonalkokole . Jour. Praktische Chemie,
vol. 88, Nov. 1913, pp. 6IH-698.
19. Whitmore, Frank C, Laughlin, Kenneth C, Matuszeski, John F., and
Surmatis, J. D.t The Polymerization of Olefins. II - The Copoly-
merization of s-Butyl and t-Butyl Alcohols "by Sulfuric Acid. Jour.
Am. Chem. Soc, vol. 63, no. 3, March I9U1, pp. 756-757.
20. Dinerstein, Robert Alvin: Synthesis of Isomeric Nonanes Employing
Zinc Alkyls. 2,2,4,^-Tetramethylpentane, 2,3,3,^-Tetramethylpentane.
Pennsylvania State College Thesis, 19^0.
50 NA.CA TN No. 12^7
21. Enyeart, Charles R.: I. The Synthesis of 2,3,3A-Tetramethylpentane.
II. The Synthesis' of 3,3-Blmethyl-l-CW.oro'butane. IH. Miscella-
neous. Pennsylvania State College. Ph.D. Thesis, 19*1-2.
22. Young, William G., and Roberts, John D.: Highly-Branched Compounds.
The Preparation of Triisopropyl Carhinol and Diisopropyl- s-3utyl-
carMnol. Jour. Am. Chem. Soc, vol. 66, no. 9, Sept. 19^,
23. Bartlett, Paul D., and Schneider, Abraham: The Synthesis of Tri- t-
Butylcarbinol and Other Highly Branched Alcohols "by Means of Sodium.
Jour. Am. Chem. Soc., vol. 67, no. 1, Jan. 19*1-5, PP» lfcL-lW-.
2k, Haller, A., end Bauer, Ed.: Alcoylation dee ce'tones aliphatiques par
1 ' intermediaire de l'amidure de sodium. Comptes Rendus, vol. 150,
March 1910, pp. 582-589.
25. Bergstrom, F. ¥.: Sodium Amide. Organic Syntheses, vol. 20,
C. F. H. Allen, ed., John Wiley & Sons, Inc. (New York, N. Y.)
I9U0, pp. 85-91.
26. Whitmore, Frank C, and Church, James M.: The isomers of "Diiso-
"butylene." Ill - Determination of Their Structure. Jour. Am. Chem
Soc, vol. 5k , no. 9, Sept. 1932, pp. 3710-371^.
27. Locquin, R., and Sung, W.: "Pennone" ou Titramethyl-2-2-3-3-
Pentanone-4. Comptes Rendus ; vol. 178, May 1924, p.. 1179*
28. Locquin, R,, and Sung, W.: Sur la "pennone" ou tltramethyl-2-2-3-3-
pentanone-4. Bulletin de la Societe Chemique de France, ser. h,
vol. 35, April 1924, pp. 753-762.
29. Whitmore, Frank C, Marker, R. E., and Plambeck, Louis, Jr.: Studies
on Hexamethylethane and Related Compounds. Jour. Am. Chem. Soc,
vol. 63, no. 6, June 19^1, pp. 1626-1630.
30. Nef, J. U.: tJber die Alkylirung der Ketone. Justus LleMgs Annalen
der Chemie, vol. 310, 1899, pp. 316-335*
31. Moersch, George: Synthetic Aliphatic Hydrocarbons of Nine to Twelve
Carbons. Pennsylvania State College, Ph.D. Thesis, 19^2.
32. Heyd, Josef William: " A Study of Compounds Containing a Neo Carbon.
Pennsylvania State College, Ph.D. Thesis, 1937.
33* Yule, J. A. C, and Wilson, C. P., Jr.: Peroxides and Gum in Gasoline.
Ind. Eng.. Chem., vol. 23, no. 11, Nov. 1931, pp. 125^-1259,
HACA TN No. 12^7 51
3^. Schurman, Iman, and Boord, Cecil E.: Syntheses In the Olefin Series
V - Completing the Survey of the Hoxenes and Including Certain
Eeptenes and Octenes. Jour. Am. Chem. Soc, vol. 55, no. 12, Dec.
1933, PP. >930-^935.-
35 • Kistiakowslcy, G. B., Ruhoff, John R», Smith, Hilton A., and Yaughan,-
W. E.: Heats of Organic Reactions. Ill - Hydrogenation of Some
Higher Olefins. Jour. Am. Chem. Soc., vol. 58, Jan. 1936, pp. 137-
36", TongTsergj, CO., Pickens, J. B., Fenske, M. E., and Whitmore, Frank C:
The Isomers of "Diisolmtylene ." H. Jour. Am. Chem. Soc, vol. 5k,
no. 9, Sept. 1932, pp. 3706-3710.
37' KuyScendall, Sidney Benson: Syntheses in the Octene Series^ Octenes of
Type III... Ohio State Univ., Ph.D. Thesis, 1935.
NACA TN No. 1247
TABLE 1.-' DISTILLATION COEtMfS
6oo toy h.o
3/l6-inch pyrex helloes
. 150 toy 2.0
3/l6- inch glass helices
200 to 5OOO
150 toy 2.0
3/32- inch stainless- steel hel-
ices from 0.010-lnoh wire
150 toy 2.2
150 1>T 2.2
3/l6-inch glass helices
125 toy 2.2
70 toy 1.1
l/l6- inoh niohrcae helloes from
1*0 toy 1.0
3/6fc-inch stainless-steel hel-
ices from 0. 006"5-lnch vire
600 toy 5.1
90 centimeter l/2-lnch cartoon
rasohig rings, then 510 centi-
meter 3/32-inch stainless-
steel helices from 0.010-inch
18 ft 13
1600 toy 10 .2
3/8-inch porcelain rasohig rings
1600 toy 5-1
50 centimeter 3/8-lnoh porcelain
rasohig rings, followed toy 1550
centimeter 3/32-lnoh stainless-
steel helloes from .010 Inch
1600 toy 2.7
127 toy 0.8
250 to 5000
127, toy 2.5
250 to 5000
19 ft 20
250 toy 2.5
250 to 5000
120 toy 3.5
3/l6-lnoh glass helices
22 to 25
183 toy 2.5
3/32-inch stainless-steel hel-
loes from 0.010-lnoh wire
500 to 5000
25 to 27
I83 toy 2.5
3/l6- inch glass helices
500 to 5000 J
COMMITTEE FOR AERONAUTICS
NACA TN No. 1247
TABLE 2 .- PHYSICAL PROPERTIES OF OOKPOUND PREPARED
[Values are believed to be precise to witbln a few units In the last place given 3
at 760 cm Bf
at 760 ■■ He
i O.O361 '
-119.86 GO. 50S
£ i 3 i3-*rimothylpontai:8
2, 2, VSrimethylhexaiu
-123. 4XH?) 126.54
2, 2, 5-f rimathylhoxac«
£i 3 1 5-Srinethylheuuu
2» 2. 3 ,3-Ictr»n8tbylp«ntaDO
2, 2,3 , 4-Ietraratthylpcntane
2>3 13 » ^•Istroaethsrlpcnbone
2 ( 2,3 ,3-IetrMothylhe sane
2,«i,U t 5-Tetr««tth7lh£iBi:»
2» 2» 5 » 5-IetrcjoetIiylhe sane
3 »3 1 % 4-Tatranathylhcxana
2> 2,3 • 3 1 ^-Pantanethylpentane
2, 2,3 , % ^antnaftthjrlpentan*
2, 3-Dlw thyl-1-lmt enc
2, 3-J)i methyl- 2-biittne
2 P 3 .3-lricfithyl-l»-p intone
2,3 f l4-Trimethyl-2-peJit«i*
3,U t li-Trinctbyl-2-pentan« (OT)
73 (100 EH
2,3 1 5-Trinttbyl-2-bcaene
58 (50 an)
2*3 »3 > tMEetraovtbyl-l-peataQe
96 (200 m
88 (200 iz
U a t)-Dimethyi-3-ebh/l-2-pGntene (CT
84 (150 ra
3 ,3-^>iiiethyl-2-i sopropyl-Mntt eno
'2 l 3 t 5 t 5~Ietreaothyl-2-hexftn«
2»3.3»% 1 ^-Pentwiiethyl-l-pentene
3,3-IHn»tlvl-3-t-batyl-l- , batene
80 (150 DD
2 ,3 -SlDethyX-2-^butaul
76 (150 m
2 f U-Din»thyI-3-«thyl-3-paiitaJBl
71 (25 «■]
96 150 ns!
94 (50 m)
94 (50 m)
109 (50 nun)
2, 1 t-Wcatliyl-'5-i60prop7l-3-pdntBiio
2, 2,3 « **» M-Pentanethyl-3-pentoool
2, 2, U-fricethyl-3-pectanono
2, 2, 4, l f-Ietr£uaethyl-3-p*ntonone
Ethyl Brine thyl acetate
87 (62 en)
3-0hloro-2, 3 , q-Tridftthylpentanel
3-Ohloro-2, 3 , 4-IrinatlylpentaneJ
82 (57 ran)
32 (45 an)
a Syoibole: nf, material became very riscoue or glaney without freezing
to a oryetailine aolid: nd r material considered too inpure to Tarrant
determination of freezing point j UP, melting point; L.B.I. , lover-boiling
^eouetrio isomer) H.B.I. , hi£aer-bolling geometric ieomerj OT, aixture
of geometrio isomers.
D Bee referenoe 5.
See referenoe 4.
^ Oaloulated fro.x data given in referenoe 13.
e The rofraotive indicoe of 2,2,3,3-tetramethylpentane wore determiaed
bv Ur. Leroy Tilton on the Optioal Instruments Section of thiB Bureau.
COMMITTEE FOR AERONAUTICS
TABLE 3.- mrraoCAKBOHS ISOUBBBD IfiOM "BOTEKE AEErLKEE"
760 an Hg
index, n^ 20
1.3531 to 1.3533
1.37*9 to 1.3752
1.3714 to I.3716
I.3761 to I.3763
1.3815 to 1.3820
1.3912 to 1.3920
1.3912 to 1.3915
3 The data in this coluux represent the amount isolated having the properties
shown. It does not constitute an exact analysis of the crude.
COMMITTEE FOR AERONAUTICS
TABES k.- TXmSZOB OF BUSOBOTILEtTE BY PSEUMUfART FRACTIOHATION
coat of total
Boiling range 1
1.392 to l.*082
butyl alcohol, other polar
101.5 to 102
1.1»0& to IJ1O88
102 to 10*
l.Ii09^ to 1.JH27
Xateraedlate, ndxtnre of
2,U,lf-trl»etlijl-l- and 2-
IX* to 107
1.M50 to 1.M60
end snail quantities of 2,3,1*-
pentanes, and other ootenes
107 to 117
1A207 to I.U238
2,3,^-TrlMethyl- and 3,M~
^Cottrell boiling-point Measurements on first and last fractions*
COMMITTEE FOP AERONAUTICS
ID PGLTKER BY HTKT.TMTWAHT HRACTTOIATION
TABLE 5.- JJH
jsxm of wn ac
cent of total
Boiling range 1
101.0 to 101.7
i.to8 to 1.1*20
2,3, 1 HTrln8thyl-
U0.1 to 112.0
1.1*21 to l.fc23
3 , U, 4-TrlM»thyl-
113.0 to 116.0
I.U25 to I.U26
^Jotfcrell liolling-point Measurements on first and last fractions.
2 A preliminary distillation of 2 liters Indicated over 10 percent gas.
COMMITTEE FOB AERONAUTICS
,.-34.3653 OhmB-O--li3.638 o
O Q ' ► o ° O i ► O
a 9 o > o o
o a < i o
° o 6 rt
o o ' o o
° O li O n O
COMMITTEE FOft AERONAUTICS
riguro 1.- rraoelng point of 2,3,5,5-totruiatbylbexaae.
NAOA TN No. 1247
P «= 760.90 urn
o 9 o ^ o
P ■ 745.91 mm
, » '
5-T et ran
P - 74
O O (
P - 7t
1 O (
I o <
o o o <!
Figure 2.- Boiling point of four representative hydrocarbons.
COMMITTEE FOR AERONAUTICS
R»t OB at peroxide formation la 2,3-dlraethyl-3-butene
10 80 30 40 50
figure 4.- Bata of peroxide formation in 2,S-dimethyl-l-butene.
COMMITTEE FDR AERONAUTICS